59 is the natural number following 58 and preceding 60.

In mathematics

Fifty-nine is the 17th smallest prime number. The next is sixty-one, with which it comprises a twin prime. 59 is an irregular prime and a safe prime. It is also a highly cototient number.

There are 59 stellations of the icosahedron. These are discussed in H. S. M. Coxeter, P. Du Val, H. T. Flather, and J. F. Petrie's book The Fifty-Nine Icosahedra.

In science

• The atomic number of praseodymium, a lanthanide

In astronomy,

Messier object M59, a magnitude 11.5 galaxy in the constellation Virgo

The New General Catalogue object NGC 59 , a magnitude 12.4 spiral galaxy in the constellation Cetus

The Saros number of the solar eclipse series which began on -1031 June 19 and ended on 249 July 27. The duration of Saros series 59 was 1280.1 years, and it contained 72 solar eclipses.

The Saros number of the lunar eclipse series which began on -729 March 30 and ended on 569 May 16. The duration of Saros series 59 was 1298.1 years, and it contained 73 lunar eclipses.

In other fields

Fifty-nine is also:

• The designation of Interstate 59, a freeway that runs from Louisiana to Georgia.
• The year AD 59, 59 BC, or 1959.
• Approximately the number of days in two lunar months.
• The model number of the Texas Instruments TI-59 calculator, one of the first programmable calculators.