18

10 11 12 13 14 15 16 17 18 19

0 10 20 30 40 50 60 70 80 90

Cardinaleighteen
Ordinal18th
(eighteenth)
Numeral systemoctodecimal
Factorization$2 \cdot 3^2$
Divisors1, 2, 3, 6, 9, 18
Roman numeralXVIII
Binary10010
Octal22
Duodecimal16

18 (eighteen) is the natural number following 17 and preceding 19. 17 ( seventeen) is the Natural number following 16 and preceding 18. 19 ( nineteen) is the Natural number following 18 and preceding 20. In mathematics Nine is a Composite number, its proper Divisors being 1 and 3. 17 ( seventeen) is the Natural number following 16 and preceding 18. 19 ( nineteen) is the Natural number following 18 and preceding 20. "Twenty" redirects here For the village in England, see Twenty Lincolnshire. This is a list of articles about Numbers ( not about Numerals. The integers (from the Latin integer, literally "untouched" hence "whole" the word entire comes from the same origin but via French "Twenty" redirects here For the village in England, see Twenty Lincolnshire. 30 ( thirty) is the Natural number following 29 and preceding 31. 40 ( forty) is the Natural number following 39 and preceding 41. This article discusses the number fifty. For the year 50 CE see 50. 60 ( sixty) is the Natural number following 59 and preceding 61. 70 ( seventy) is the Natural number following 69 and preceding 71. 80 ( eighty) is the Natural number following 79 and preceding 81. 90 ( ninety) is the Natural number preceded by 89 and followed by 91. This article describes cardinal numbers in mathematics For cardinals in linguistics see Names of numbers in English. In linguistics ordinal numbers are the words representing the rank of a number with respect to some order in particular order or position (i A numeral system (or system of numeration) is a Mathematical notation for representing numbers of a given set by symbols in a consistent manner In Mathematics, factorization ( also factorisation in British English) or factoring is the decomposition of an object (for In Mathematics, a divisor of an Integer n, also called a factor of n, is an integer which evenly divides n without Roman numerals are a Numeral system originating in ancient Rome, adapted from Etruscan numerals. The binary numeral system, or base-2 number system, is a Numeral system that represents numeric values using two symbols usually 0 and 1. The octal Numeral system, or oct for short is the base -8 number system and uses the digits 0 to 7 The duodecimal system (also known as base -12 or dozenal) is a Numeral system using twelve as its base. In Mathematics and Computer science, hexadecimal (also base -, hexa, or hex) is a Numeral system with a In Mathematics, a natural number (also called counting number) can mean either an element of the set (the positive Integers or an 17 ( seventeen) is the Natural number following 16 and preceding 18. 19 ( nineteen) is the Natural number following 18 and preceding 20.

## In mathematics

Eighteen is a composite number, its proper divisors being 1, 2, 3, 6 and 9. A composite number is a positive Integer which has a positive Divisor other than one or itself In Mathematics, a divisor of an Integer n, also called a factor of n, is an integer which evenly divides n without Mathematics For any number x: x ·1 = 1· x = x (1 is the multiplicative identity In mathematics Two has many properties in Mathematics. An Integer is called Even if it is divisible by 2 ---- In mathematics Three is the first odd Prime number, and the second smallest prime In mathematics Six is the second smallest Composite number, its proper Divisors being 1, 2 and 3. In mathematics Nine is a Composite number, its proper Divisors being 1 and 3. Three of these divisors (3, 6 and 9) add up to 18, hence 18 is a semiperfect number. In Mathematics, a semiperfect number or pseudoperfect number is a Natural number n that is equal to the sum of all or some of its Proper

It is a heptagonal number, and as the sum of the first three pentagonal numbers, it is a pentagonal pyramidal number. A heptagonal number is a Figurate number that represents a Heptagon. A pentagonal number is a Figurate number that extends the concept of triangular and Square numbers to the Pentagon, but unlike the first A pentagonal pyramidal number is a Figurate number that represents the number of objects in a pyramid with a Pentagonal base It is also the sum of the totient function for the first seven integers. In Number theory, the totient \varphi(n of a Positive integer n is defined to be the number of positive integers less than or equal to

The aliquot sum of 18 is 21 and its aliquot sequence is (18,21,11,1,0). In Mathematics, and specifically in Number theory, a divisor function is an Arithmetical function related to the Divisors of an Integer In Mathematics, an aliquot sequence is a recursive sequence in which each term is the sum of the Proper divisors of the previous term

In base 10 it is a Harshad number. A Harshad number, or Niven number, is an Integer that is divisible by the sum of its digits in a given number base.

18, aside from 0, is the only number that equals twice the sum of its decimal digits.

## In religion and literature

• The Hebrew word for "life" is חי (chai), which has a numerical value of 18. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton This article pertains to the chemical element For other uses see Argon (disambiguation. Chai (xai occasionally) is a Symbol and word that figures prominently in Jewish culture and consists of the letters of the Hebrew alphabet Gematria or gimatria ( Rabbinic Hebrew he גימטריה) is a system of assigning numerical value to an Alphabet. Consequently, the custom has arisen in Jewish circles to give donations and monetary gifts in multiples of 18 as an expression of blessing for long life.
• In Judaism, in the Talmud; Pirkei Avot (5:25), Rabbi Yehudah ben Teime gives the age of 18 as the appropriate age to get married ("Ben shmonah esra lechupah", at eighteen years old to the Chupah (marriage canopy)). Judaism (from the Greek Ioudaïsmos, derived from the Hebrew יהודה Yehudah, " Judah " in Hebrew יַהֲדוּת Yahedut The Talmud ( Hebrew: he תַּלְמוּד is a record of Rabbinic discussions pertaining to Jewish law, ethics, customs and history Pirkei Avot / Ovos (Ethics of the Fathers פרקי אבות is a tractate of the Mishna composed of ethical maxims of the Rabbis of the Mishnaic period A chuppah ( חוּפָּה) (also spelled hupah, chupah, or chuppa - plural chuppot or chuppahs, Hebrew (See Coming of age, Age of majority). Coming of age is a young person's transition from Adolescence to Adulthood The age at which this transition takes place varies in society as does the nature The age of majority is the threshold of Adulthood as it is conceptualized (and recognized or declared in Law.
• Joseph Heller's novel Catch-22 was originally named Catch-18 because of the Hebrew meaning of the number, but was amended to the published title to avoid confusion with another war novel, Mila 18. Catch-22 is a satirical, historical Novel by the American author Joseph Heller, first published in 1961 [1]
• There are 18 chapters in the Bhagavad Gita, which is contained in the Mahabharata, which has 18 books. The Kurukshetra War which the epic depicts, is between 18 armies (11 on the Kuru side, 7 on the Pandava). The Kurukshetra War ( Devangari: कुरुक्षेत्र युद्ध forms an essential component of the Hindu epic Mahābhārata Indian epic poetry is the Epic poetry written in the Indian subcontinent. Year 7 ( VII) was a Common year starting on Saturday (link will display the full calendar of the Julian calendar. In the Hindu epic Mahābhārata, the Pandava (or Pandawa brothers ( Sanskrit: पाण्‍डव pāṇḍavaḥ are the five acknowledged sons of

## As lucky or unlucky number

• In Chinese tradition, the number 18, normally 十八 (shí bā), can also be read as 幺八 (yāo bā), which sounds like 要发 (yào fā), meaning that one is going to prosper. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National The word tradition comes from the Latin traditionem acc of traditio which means "a giving up delivering up surrendering" and is used in a number of Thus, building floors numbered "18" are often very expensive in China

## Age 18

In many parts of the world, 18 is the age minimum for purchasing tobacco and alcoholic beverages. Tobacco is an Agricultural product recognized as an addictive drug processed from the fresh Leaves of plants in the genus Nicotiana. It is also the voting age in many countries. During the Vietnam War, Americans could be drafted at an age as low as 18, but were not allowed to vote in most states until they were 21. The Vietnam War, also known as the Second Indochina War, or the Vietnam Conflict, occurred in Vietnam, Laos and Cambodia A movement spread to lower the voting age, and in 1971, the Twenty-sixth Amendment extended a guarantee of suffrage to anyone 18 years or older in all states. Year 1971 ( MCMLXXI) was a Common year starting on Friday (link will display full calendar of the 1971 Gregorian calendar. The voting age was lowered from 21 to 18 in the U.K. and many other nations around that time. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located

Eighteen is also the age in many countries at which a person may appear in a pornographic video, or express legal consent to sexual relations with another. Consent as a term of jurisprudence is a possible defence (an Excuse or justification against civil or criminal liability

In addition, eighteen year-olds in the United States have the right to bear arms, own property, marry without parental consent, get an abortion, donate their body to science, and serve on a jury. With these new privileges come responsibility: eighteen year-olds are tried as adults in court.

In the United Kingdom, eighteen-year-olds can purchase tobacco, alcohol, pornography, go to war, vote, and model for pornography; (but the age of consent is 16). The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Tobacco is an Agricultural product recognized as an addictive drug processed from the fresh Leaves of plants in the genus Nicotiana. In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon Pornography or porn is the explicit depiction of Sexual subject matter with the sole intention of sexually exciting the viewer War is an international relations Dispute, characterized by organized Violence between National Military units Pornography or porn is the explicit depiction of Sexual subject matter with the sole intention of sexually exciting the viewer

In many countries 18 is the age of majority. The age of majority is the threshold of Adulthood as it is conceptualized (and recognized or declared in Law.

In many states in which one can obtain a learner's permit without parental consent.

Minimum age at which one can be admitted to, rent, or buy an MPAA rated NC-17 movie. The Motion Picture Association of America's film-rating system is used in the U This is also the age at which one can see an NC-17 rated movie. The Motion Picture Association of America's film-rating system is used in the U

Minimum age at one can play, rent, or buy an ESRB rated AO game. The Entertainment Software Rating Board ( ESRB) is a self-regulatory organization that applies and enforces ratings, Advertising guidelines and

Minimum age at which one can rent, buy, or buy tickets to an 18A rated film in Canada without being accompanied by an adult. Ratings in Canada are provincal, so they may vary. A film can be 18A in some provinces and 14A in other province. A film can also be 18A in some provinces and R in other provinces. 18 is also the minimum age at which one can view, rent, or buy an R or an A rated movie.

Minimum age at which one can buy, rent, view, or buy tickets to an 18+ rated movie in the Canadian province of Quebec.

Minimum legal age to drink and/or buy alcohol in many countries in the world.

Minimum age at which one can get a full driver's license in many U. S state and Canadian provinces.

Minimum age to drive a car in many countries in the world. See also: 18 certificate, Coming of age

Minimum age in which one can enter a pub or a club in the UK. The 18 certificate is issued by the British Board of Film Classification (BBFC to state that in its opinion a film or video recording should not be seen or purchased Coming of age is a young person's transition from Adolescence to Adulthood The age at which this transition takes place varies in society as does the nature

Minimum age at wich you can legally buy marijuana in the Netherlands. Cannabis, also known as marijuana or marihuana, or ganja (from Hindi / Sanskrit: गांजा gānjā hemp) is a

## In other fields

Eighteen is also:

• a 2005 movie directed by Richard Bell and starring Brendan Fletcher and Alan Cumming. Richard Bell may refer to Richard Bell (artist, Australian Artist Richard Bell (director, Canadian writer and director Brendan Fletcher (born December 15, 1981) is a Canadian Actor. Alan Cumming (born 27 January 1965 is a Scottish film and stage Actor, perhaps best known for his supporting roles as Boris Grishenko in the
• Jersey number of NHL star Marian Hossa. Marián Hossa (born January 12 1979) is a Slovak professional Ice hockey right winger who currently plays for the Detroit Red
• Bobby Labonte's car number in the NASCAR Winston Cup Series when he won the 2000 Championship. Robert Alan Labonte (born May 8, 1964 in Corpus Christi Texas) is an American Race car driver and drives the #43 Cheerios The 2000 NASCAR Winston Cup Season began on Sunday February 13 and ended on Sunday November 20. This is J. J. Yeley's car number until the end of the 2007 Nextel Cup Season. Christopher Beltram Hernandez Yeley (born October 5, 1976) is a NASCAR racecar driver from Phoenix Arizona. 2007 in NASCAR can refer to any of the following NASCAR national series 2007 NASCAR Nextel Cup Series - The top racing series in NASCAR Kyle Busch will take the car number in 2008. Kyle Thomas Busch (born May 2, 1985 in Las Vegas, Nevada) nicknamed "Rowdy Busch" "Wild Thing" or "Shrub" 2008 in NASCAR can refer to any of the following NASCAR national series 2008 NASCAR Sprint Cup Series - The top racing series in NASCAR
• A 2002 album by electronic artist Moby. 18 is a 2002 album by electronic artist Moby. It sees Moby following a similar direction to that of his previous album Play, Richard Melville Hall, also known as Moby (born September 11, 1965 in Harlem, New York) is an American DJ
• The number of holes in a stipulated round of golf
• The number of chapters into which James Joyce's epic novel Ulysses is divided
• Russ Wheeler's car number in the film Days of Thunder
• A slang term used in association football for the Penalty Area
• The number of wheels on the most common type of North American tractor-trailer truck, which are hence often called 18-wheelers
• The customary percentage to tip a waitress in a restaurant by groups of four or more
• The number of the French department Cher and the Turkish province Bitlis
• DVD-18 is double-sided, double-layered DVD format
• A Canon error message, see E18 error
• 18 (Dragon Ball), a fictional character in the metaseries Dragon Ball. 88 ( eighty-eight) is the Natural number following 87 and preceding 89.
• 18th Street gang, a Hispanic American gang
• Jersey number of football player Peyton Manning. 18th Street Gang is a largely- Hispanic Los Angeles -based Street gang. Peyton Williams Manning (born March 24 1976 is an American football Quarterback who currently plays for the Indianapolis Colts of the National Football
• Jersey number of football player Sage Rosenfels. Sage Rosenfels (born March 6, 1978 in Maquoketa, Iowa) is an American football Quarterback for the Houston Texans
• Jersey number of former basketball player Phil Jackson
• Jersey number of baseball player Héctor Luna. Philip Douglas Jackson (born September 17 1945 in Deer Lodge, Montana) is a retired American Basketball player and current coach of the Héctor R Luna (born February 1, 1980 in Monte Cristi, Dominican Republic) is a Major League Baseball player for the Toronto
• Uniform number of former baseball player Don Larsen. Donald James Larsen (born August 7, 1929 in Michigan City Indiana) was a Major League Baseball pitcher for 14 seasons The number shows prominently in a photograph taken just before the last pitch he made in his perfect game in the 1956 World Series. A perfect game is defined by Major League Baseball as a game in which a Pitcher (or combination of pitchers pitches a victory that lasts a minimum The 1956 World Series of Major League Baseball was played between the New York Yankees (representing the American League) and the defending champion (When this picture was printed in Baseball's Unforgettable Games by Joseph Reichler and Ben Olan in 1960, they gave it the caption "The Writing on the Wall. ")
• The Hindu epic Mahabharata has eighteen sections, involves eighteen armies and is about a war fought over eighteen days
• The sacred literature of the Hindus known as Bhagavad Gita has eighteen chapters.
• In some countries the number 18 means blood (relative)
• In the Chinese mythos, Hell has 18 levels
• In Chinese folklore, the Shaolin temple had a group of 18 Bronze Monks. Initiates could only be considered full graduates of Shaolin martial arts if they could defeat them in combat.
• Eighteen Visions (often abbreviated to 18V), an alternative metal/metalcore band from Ornage County, California. Eighteen Visions (sometimes shortened to 18V or 18 Visions) were an Orange County California, United States -based band signed to Alternative metal is an eclectic form of Heavy metal music that gained popularity in the early 1990s alongside grunge. Metalcore is an umbrella term used to describe fusion genres that incorporate elements of the Hardcore punk and heavy metal genres
• Eighteen Eighteen, a South African Rap artist.

## Historical years

A.D. 18, 18 B.C., 1918, 2018, etc. Year 18 was a Common year starting on Saturday (link will display the full calendar of the Julian calendar. Year 18 BC was a Common year starting on Thursday (link will display the full calendar of the Julian calendar. Year 1918 ( MCMXVIII) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar (or a Common 2018 ( MMXVIII) will be a Common year starting on Monday of the Gregorian calendar.