|Divisors||1, 2, 4, 13, 26, 52|
Fifty-two is the 6th Bell number and a decagonal number. It is an untouchable number, since it is never the sum of proper divisors of any number, and it is a noncototient since it is never the answer to the equation x − φ(x).
- Messier object M52, a magnitude 8.0 open cluster in the constellation Cassiopeia, also known as NGC 7654.
- The New General Catalogue object NGC 52, a spiral galaxy in the constellation Pegasus.
In other fields
- The approximate number of weeks in a year. 52 weeks is 364 days, while the tropical year is 365.24 days long. According to ISO 8601, most years have 52 weeks while some have 53.
- A significant number in the Maya calendar
- On the modern piano, the number of white keys (notes in the C major 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 Pickup
- "52 Pick-Up" is a 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.
- The number of 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.
- "Sloane's A000110 : Bell or exponential numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
- "Sloane's A001107 : 10-gonal (or decagonal) numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
- "Sloane's A005114 : Untouchable numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
- "Sloane's A005278 : Noncototients". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.