23 (number)

23 (twentythree) is the natural number following 22 and preceding 24.
Cardinal  twentythree 
Ordinal  twentythird 
Factorization  prime 
Roman numeral  XXIII 
Binary  10111 
Hexadecimal  17 
Contents 
In mathematics
Twentythree is the ninth prime number, the sequence continues 29, 31, 37, 41,... Twentythree is also the fifth factorial prime, the fifth Sophie Germain prime, the fourth safe prime, the second Woodall prime, and the second SmarandacheWellin prime.
23 also has the distinction of being one of two integers that can't be expressed as the sum of 8 cubes (we allow 0^3 since zero is indeed an integer). The other integer is 239.
23 is a WedderburnEtherington number.
23 is a highly cototient number.
23 is the smallest odd prime that is not a twin prime.
23 is the ninth prime number, and 9 is 3 squared. This produces the interesting symmetry of 2332.
In science
 The atomic number of vanadium
 The number of chromosomes in a human germline cell
In astronomy,
 Messier object M23, a magnitude 6.0 open cluster in the constellation Sagittarius
 The New General Catalogue object (http://www.ngcic.org/) NGC 23, a magnitude 12.0 barred spiral galaxy in the constellation Pegasus
 The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/SEsaros/SEsaros1175.html) of the solar eclipse series which began on 2145 May 7 and ended on 865 June 15. The duration of Saros series 23 was 1280.1 years, and it contained 72 solar eclipses.
 The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/LEsaros/LEsaros1175.html) of the lunar eclipse series which began on 1843 February 14 and ended on 527 April 14. The duration of Saros series 23 was 1316.2 years, and it contained 74 lunar eclipses.
Occult significance
 The sacred number (along with 17 and 5) of Eris, goddess of discord, according to the Principia Discordia; it is the number of the Illuminati.
 Like 13, sometimes considered lucky or otherwise significant (as in the occult writings of Aleister Crowley and William S. Burroughs); see the 23 enigma.
 Robert Anton Wilson's book, Cosmic Trigger I: Final Secret of the Illuminati, lists 23 as a cosmic number with strong connections to arcane magic and synchronicity. Numerous people have claimed to see 23's everywhere (the 23 curse) prior to enormous success and fruitfulness.
 In many other of Wilson's works (especially The Illuminatus! Trilogy and Principia Discordia) 23 is given special importance. Many Discordians use this number for any number of purposes.
 One of the "Numbers" on the TV show Lost The list of the numbers is: 4 8 15 16 23 42
In other fields
Twentythree is:
 In early 20th century United States slang, it meant to leave a place. (From the phrase 23 skiddoo ; the origins of the phrase are largely unknown).
 23, a German movie about Karl Koch.
 A telegraphers' code meaning "line break".
 Michael Jordan's jersey number when he played for the Chicago Bulls basketball team (the second time) as well as the Washington Wizards. The number now has special significance throughout sports, especially in basketball. Many athletes wear the number 23 either as a tribute to Jordan or because they would like to "be like Mike".
 David Beckham's squad number at Real Madrid football (soccer) club, inspired by the aforementioned Jordan.
 When mathematician John Forbes Nash suffered from schizophrenic delusions, he said that Life Magazine had run a cover story of him disguised as Pope John XXIII as his name was John and his favorite prime number was 23.
 Nash published a total of 23 scientific articles.
 The number of chromosomes in a human germline cell.
 The largest integer number of hours in a day.
 Manchester City F.C. have not assigned the squad number 23 to any player since 2003. This is due to the fact that MarcVivien Foé, the player who collapsed and died while playing for Cameroon on June 26 2003, had held this squad number at Manchester City.
 Computers: decimal 23 is octal 027 and hexadecimal 0x17; The ASCII character set for decimal 23 is ETBde:Dreiundzwanzig
es:Veintitrés eo:Dudek tri fr:23 (nombre) ko:23 ia:23 it:Ventitré he:23 (מספר) nl:Drieëntwintig ja:23 no:23 (tall) pt:Vinte e três sv:23 (tal) zh:23