53 (number) - Definition and Overview

53 is the natural number following 52 and preceding 54.

In mathematics

Fifty-three is the 16th smallest prime number. The next is fifty-nine. Fifty-three is also a Sophie Germain prime, and the sum of five consecutive primes (5 + 7 + 11 + 13 + 17). But 53 can not be expressed as the sum of any integer and its base 10 digits, making 53 a self number.

53 written in hexadecimal is 35, that is, the same characters used in the decimal representation, but reversed. Three multiples of 53 share this property: 371 = 173₁₆, 5141 = 1415₁₆, 99481 = 14899₁₆.

In science

• The atomic number of iodine

In astronomy,

Messier object M53, a magnitude 8.5 globular cluster in the constellation Coma Berenices

The New General Catalogue object (http://www.ngcic.org/) NGC 53, a magnitude 12.6 barred spiral galaxy in the constellation Tucana

The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/SEsaros/SEsaros1-175.html) of the solar eclipse series which began on -1295 August 26 and ended on 220 February 21. The duration of Saros series 53 was 1514.5 years, and it contained 85 solar eclipses.

The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/LEsaros/LEsaros1-175.html) of the lunar eclipse series which began on -993 June 5 and ended on 287 July 12. The duration of Saros series 53 was 1280.1 years, and it contained 72 lunar eclipses.

In other fields

Fifty-three is also:

• The code for international direct dial phone calls to Cuba.
• In the title of the 1912 movie North of Fifty Three, remade in 1917.
• The number of short poems in the book Rumi Birdsong by Jelaluddin Rumi.
• The year AD 53, 53 BC, and 1953.