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52 (number) - Definition and Overview |
| Related Words: M, Account, Act, Afterpiece, Aggregate, Army, Art, Article, Batch, Beat, Billion, Bit, Blood, Book |
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52 is the natural number following 51 and preceding 53.
In mathematics
Fifty-two is the 5th 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).
In science
In astronomy,
- Messier object M52, a magnitude 8.0 open cluster in the constellation Cassiopea, also known as
- The New General Catalogue object (http://www.ngcic.org/) NGC 52, a spiral galaxy in the constellation Pegasus
- The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/SEsaros/SEsaros1-175.html) of the solar eclipse series which began on -1378 August 14 and ended on 155 February 19. The duration of Saros series 52 was 1532.5 years, and it contained 86 solar eclipses.
- The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/LEsaros/LEsaros1-175.html) of the lunar eclipse series which began on -1026 May 27 and ended on 204 June 29. The duration of Saros series 52 was 1280.1 years, and it contained 72 lunar eclipses.
In other fields
Fifty-two is also:
- The number of weeks in a year.
- The number of sons of Nebo in the Census of men of Israel upon return from exile (Holy Bible, Ezra 2:29).
- On the 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 Pick-up.
- The code for international direct dial phone calls to Mexico.
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