79 is the natural number following 78 and preceding 80.

In mathematics

Seventy-nine is the 22nd prime number. The next is eighty-three. Seventy-nine is a permutable prime, with ninety-seven. 79 is a strictly non-palindromic number, it is not palindromic in any base from base 2 to base 77.

In science

• The atomic number of gold

In astronomy,

Messier object M79, a magnitude 8.5 globular cluster in the constellation Lepus

The New General Catalogue object NGC 79 , a galaxy in the constellation Andromeda

The Saros number of the solar eclipse series which began on -434 May 21 and ended on 828 June 16. The duration of Saros series 79 was 1262.1 years, and it contained 71 solar eclipses.

The Saros number of the lunar eclipse series which began on -150 February 16 and ended on 1166 April 12. The duration of Saros series 79 was 1316.2 years, and it contained 74 lunar eclipses.

In other fields

Seventy-nine is also:

• The designation of Interstate 79, a freeway that runs from West Virginia to Pennsylvania.
• The number of original Star Trek episodes, not counting the first pilot, "The Cage", which was enclosed into "The Menagerie".
• The year AD 79, 79 BC, or 1979.