22 (number)

← 21 22 23 →
← 20 21 22 23 24 25 26 27 28 29 → List of numbers — Integers ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	twenty-two
Ordinal	22nd (twenty-second)
Factorization	2 × 11
Divisors	1, 2, 11, 22
Roman numeral	XXII
Binary	101102
Ternary	2113
Quaternary	1124
Quinary	425
Senary	346
Octal	268
Duodecimal	1A12
Hexadecimal	1616
Vigesimal	1220
Base 36	M36

22 (twenty-two) is the natural number following 21 and preceding 23.

In mathematics

Twenty-two is an even composite number, its proper divisors being 1, 2 and 11. 22 is the sixth discrete semiprime and the fourth in the (2 × q) family. With 21 it forms the second discrete semiprime pair. 22 has an aliquot sum of 14 and is the fifth composite number found in the 7-aliquot tree. It has a 7-member aliquot sequence 22, 14, 10, 8, 7, 1, 0 of which the next two members are themselves discrete semiprimes, 22 is the first discrete semiprime exhibiting this property. 169 also has 14 as its aliquot sum. 22 is itself the aliquot sum of two numbers 20, 38.

Twenty-two is a pentagonal number and a centered heptagonal number. When cutting a circle with just six line segments, the maximum number of pieces that can be so created is 22,^[1] thus 22 is a central polygonal number (see lazy caterer's sequence).

The sum of the totient function for the first eight integers is 22. 22 is a Perrin number, preceded in the sequence by 10, 12, 17.

22 divided by 7 approximates the irrational number π, the ratio of the circumference of a circle to its diameter.

Since it is possible to find sequences of 22 consecutive integers such that each inner member shares a factor with either the first or the last member, 22 is an Erdős–Woods number.

It is a Smith number in base 10.

In physics and chemistry

• The atomic number of titanium is 22.

In religion

• There are 22 letters in the Hebrew alphabet.
• In the Kabbalah, there are 22 paths between the Sephirot.

In playing cards

• Traditional Tarot decks have 22 cards with allegorical subjects. These serve as trump cards in the game. The Fool is usually a kind of wild-card among the trumps and unnumbered, so the highest trump is numbered 21. Occult Tarot decks usually have 22 similar cards which are called Major Arcana by fortune-tellers. Occultists have related this number to the 22 letters of the Hebrew alphabet and the 22 paths in the Kabbalistic Tree of Life.

In sports

• In rugby union:
  • The "22" is a line in each half of the field which is 22 meters from the respective try line. It has significance in a number of laws particularly relating to kicking the ball away.
• In Australian rules football:
  • Each team is allowed a squad of 22 players (18 on the field and 4 interchanges).
  • In the top-level Australian Football League, each team plays 22 matches in the regular (or "home-and-away") season.
• 22 is the number of players on the field in a football (soccer) match, and also the number of players on the field at any one time in an American football match.
• The jersey number 22 has been retired by several North American sports teams in honor of past playing greats:
  • In Major League Baseball:
    • The Baltimore Orioles, for Hall of Famer Jim Palmer.
  • In the NBA:
    • The Boston Celtics, for Hall of Famer Ed Macauley.
    • The Cleveland Cavaliers, for Larry Nance.
    • The Dallas Mavericks, for Rolando Blackman.
    • The Houston Rockets and Portland Trail Blazers, both for Hall of Famer Clyde Drexler.
    • The Los Angeles Lakers, for Hall of Famer Elgin Baylor.
    • The Lakers have separately honored #22 for Hall of Famer Slater Martin, who wore the number before Baylor when the team was the Minneapolis Lakers.
    • The New York Knicks, for Hall of Famer Dave DeBusschere.
  • In the NFL:
    • The Baltimore Colts retired #22 for Buddy Young. Since the team's controversial relocation to Indianapolis, the current Indianapolis Colts have not retired any numbers, but continue to honor all numbers retired by the franchise in Baltimore.
    • The Detroit Lions, for Hall of Famer Bobby Layne.
    • The Dallas Cowboys have a policy of not retiring numbers. However, the team has not issued #22 since Hall of Famer Emmitt Smith left the team in 2002.
  • In the NHL:
    • The New York Islanders, for Hall of Famer Mike Bossy.
• The length of a cricket pitch is 22 yards.
• "22" is a common name for the .22 calibre .22 Long Rifle cartridge.
• "22" is the number of a car in NASCAR's Sprint Cup Series currently owned by Penske Racing. Joey Logano has the Sprint Cup ride in 2014.
• "22" was the number of Lewis Hamilton's McLaren-Mercedes in 2008 and is the number of Jenson Button's Brawn-Mercedes in 2009, both winning the drivers' championship that year.

In music

• The name of a song by punk band Millencolin.
• In Jay-Z's song "22 Two's", he rhymes the words: too, to and two, 22 times in the first verse.
• Iron Maiden has a song named "22 Acacia Avenue".
• Death Metal band Hypocrisy album "Catch 22" released in year 2002.
• Lily Allen has a song titled "22" from her album It's Not Me, It's You.
• Paul Weller has a song and album named 22 Dreams. The album contains 22 songs on it, including the song "22 Dreams".
• The Norwegian electronica project Ugress uses 22 as a recurring theme. All four albums features a track with 22 in the title.
• Taylor Swift has a song from her fourth album Red titled "22".
• Ashbury Heights has a song titled "The Number 22" from album The Looking Glass Society.

In journalism, literature, fashion, art, film and television

• Catch-22, the 1961 novel (and its 1970 film version) by Joseph Heller, which consequently gave rise to the expression "catch-22"
• Twenty Two, Season 2–episode 17 (February 10, 1961) of the 1959-64 TV series The Twilight Zone in which a hospitalized dancer has nightmares about a sinister nurse inviting her to Room 22, the hospital morgue.
• Revista 22, a magazine published in Romania
• There are 22 stars in the Paramount Pictures logo.

In weights and measures

• The number of yards in a chain.

In computing

• The standard port number for the Secure Shell protocol
• A quotation mark (in a URL it appears as a "%22")

In technology

• 22 is the designation of the USAF stealth fighter, the F-22 Raptor.
• .22 Long Rifle

In photography

• f/22 is the largest f-stop (and thus smallest aperture) available on most lenses made for single-lens reflex cameras

In jargon

• In French, "22" is used as a phrase to warn of the coming of the police (typically "22, v'là les flics !", "22, here come the cops!")

In other fields

Twenty-two may also refer to:

• The number of the French department Côtes-d'Armor
• In bingo, 22 is referred to as 'Two Little Ducks'

See also

• Catch 22 (disambiguation)
• Synchronicity
• 22 (numerology)

References

1. Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1986): 31

External links

• The Number 22 at The Database of Number Correlations