52 (number)

← 51 52 53 →
← 50 51 52 53 54 55 56 57 58 59 → List of numbers Integers ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	fifty-two
Ordinal	52nd (fifty-second)
Factorization	22 × 13
Divisors	1, 2, 4, 13, 26, 52
Greek numeral	ΝΒ´
Roman numeral	LII
Binary	1101002
Ternary	12213
Senary	1246
Octal	648
Duodecimal	4412
Hexadecimal	3416

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 (p², q) where q is a higher prime. It is the sixth of this form and the fifth of the form (2².q).
• 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 (52,46,26,16,15, 9,4,3,1,0) 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 x − φ(x) for any x. ^[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 NGC 52, a spiral galaxy in the constellation Pegasus.

In other fields

The piano has 52 white keys.

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 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.

Historical years

52 BC, AD 52, 1052, 1952 etc.

See also

• B52 (disambiguation)
• List of highways numbered 52

References

1. "Sloane's A000110 : Bell or exponential numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
2. "Sloane's A001107 : 10-gonal (or decagonal) numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
3. "Sloane's A005114 : Untouchable numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
4. "Sloane's A005278 : Noncototients". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
5. "Sloane's A053701 : Vertically symmetric numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-08.