52 (number) explained

Number:	52
Divisor:	1, 2, 4, 13, 26, 52

52 (fifty-two) is the natural number following 51 and preceding 53.

In mathematics

Fifty-two is

• a composite number; a square-prime, of the form where is some prime larger than It is the sixth of this form and the fifth of the form
• the 5th Bell number,^[1] the number of ways to partition a set of 5 objects.
• a decagonal number.^[2]
• with an aliquot sum of 46; within an aliquot sequence of seven composite numbers to the prime in the 3-aliquot tree. This sequence does not extend above 52 because it is,
• an untouchable number, since it is never the sum of proper divisors of any number,^[3] and it is
• a noncototient since it is not equal to for any ^[4]
• a vertically symmetrical number.^[5]

In science

• The atomic number of tellurium

Astronomy

• Messier object M52, a magnitude 8.0 open cluster in the constellation Cassiopeia, also known as NGC 7654.
• The New General Catalogue object ^[6] a spiral galaxy in the constellation Pegasus.

In other fields

Fifty-two is:

• The approximate number of weeks in a year. 52 weeks is 364 days, while the tropical year is 365.24 days long. According to most years have 52 weeks while some have 53.
• A significant number in the Mayan calendar
• On the modern piano, the number of white keys (notes in the scale)
• The number of cards in a standard deck of playing cards, not counting Jokers or advertisement cards
  • The name of a practical joke card game 52 Pick-Up is a 1986 film starring Roy Scheider and Ann Margaret
• The code for international direct dial phone calls to Mexico
• A weekly comic series from DC Comics entitled 52 has 52 issues, with a plot spanning one full year.
• The New 52 is a 2011 revamp and relaunch by DC Comics of its entire line of ongoing monthly superhero books.
• There are 52 letters in the English alphabet, if majuscules are distinguished from minuscules
• The number of the French department Haute-Marne
• 52nd Street (disambiguation)
• 52 Hand Blocks, a variant of the martial art jailhouse rock.
• 52 is the car number of retired NASCAR driver Jimmy Means
• 52 American hostages were held in the Iran hostage crisis
• The number of the laps of the British Grand Prix since 2010.

Historical years

52 BC, AD 52, 1952, 2052 etc.

See also

• B52 (disambiguation)
• List of highways numbered 52

Notes and References

1. Web site: Bell, or exponential numbers . Sloane's A000110 . The On-Line Encyclopedia of Integer Sequences . OEIS Foundation (oeis.org) . 2016-05-30 . dmy-all.
2. Web site: 10-gonal (or decagonal) numbers . Sloane's A001107 . The On-Line Encyclopedia of Integer Sequences . OEIS Foundation (oeis.org) . 2016-05-30 . dmy-all.
3. Web site: Untouchable numbers . Sloane's A005114 . The On-Line Encyclopedia of Integer Sequences . OEIS Foundation (oeis.org) . 2016-05-30 . dmy-all.
4. Web site: Noncototients . Sloane's A005278 . The On-Line Encyclopedia of Integer Sequences . OEIS Foundation (oeis.org) . 2016-05-30 . dmy-all.
5. Web site: Vertically symmetric numbers . Sloane's A053701 . The On-Line Encyclopedia of Integer Sequences . OEIS Foundation (oeis.org) . 2022-05-08 . dmy-all.
6. Web site: NGC 52 . Spiral galaxies. NGC+I Project (ngcicproject.org) . dead . ngcicproject.org . https://web.archive.org/web/20130115035321/http://ngcicproject.org/ . 2013-01-15 . dmy-all.