83 is the natural number following 82 and preceding 84.

In mathematics

Eighty-three is the sum of three consecutive primes (23 + 29 + 31) as well as the sum of five consecutive primes (11 + 13 + 17 + 19 + 23).

It is also the 23rd prime number, following seventy-nine and preceding eighty-nine, a Sophie Germain prime and a safe prime. It is also a highly cototient number.

In astronomy

• Messier object M83, a magnitude 8.5 spiral galaxy in the constellation Hydra, also known as the Southern Pinwheel Galaxy
  

  

  Southern Pinwheel Galaxy
• The New General Catalogue object NGC 83 , a magnitude 12.3 elliptical galaxy in the constellation Andromeda
• The Saros number of the solar eclipse series which began on -210 May 5 and ended on 1052 May 30. The duration of Saros series 83 was 1262.1 years, and it contained 71 solar eclipses. The Saros number of the lunar eclipse series which began on -197 August 22 and ended on 1318 February 16. The duration of Saros series 83 was 1514.5 years, and it contained 85 lunar eclipses.

In other fields

Eighty-three is also:

• The atomic number of bismuth
• the hours in 83 Hours 'Til Dawn
• the model number of Bell XP-83
• the number of the French department Var
• the designation of Interstate 83, a freeway that runs from Maryland to Pennsylvania; European route E83 from Bjala to Sofia
• The ISBN Group Identifier for books published in Poland
• The year AD 83, 83 BC, or 1983.