**Eighty-three**(83, LXXXIII) is the natural number following eighty-two and preceeding eighty-four. It is the sum of three consecutive primes (23 + 29 + 31) as well as the sum of five consecutive primes (11 + 13 + 17 + 19 + 23).

- Hexadecimal: 53
- Binary: 01010011
- Factors: 1, 83
- the 23rd prime number, following seventy-nine and preceeding eighty-nine
- Ordinal number: eighty-third

- the atomic number of bismuth (Bi)
- the hours in
*83 Hours 'Til Dawn* - the model number of Bell XP-83
- the Messier number of M83, the Southern Pinwheel Galaxy
- 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 year AD 83 or AD 1983.