117 is the natural number following 116 and preceding 118.

Cardinal	one hundred [and] seventeen
Ordinal	117th
Factorization
Divisors	3, 9, 13, 39
Roman numeral	CXVII
Binary	1110101
Hexadecimal	75

One hundred seventeen is the smallest possible length of the longest side of a Heronian tetrahedron (one whose sides are all rational numbers). It is also a pentagonal number and a Harshad number.

• In astronomy, the Saros number of the solar eclipse series which began on 792 June 24 at 05:51:16 UT and will end on 2054 August 3 at 18:01:55 UT. The duration of Saros series 117 is 1262.11 years, and it contains 71 solar eclipses.
• The Saros number of the lunar eclipse series which began on 1094 April 3 at 17:26:38 UT and will end on 2374 May 26 at 19:33:35 UT. The duration of Saros series 119 is 1280.14 years, and it contains 72 lunar eclipses.
• The NGC (New General Catalog) [1] object 117, a 15th magnitude spiral galaxy in the constellation Cetus

One hundred seventeen is also:

• The film format used by Kodak's first Brownie camera. See 120 film.
• A substitute for the number 17, which is considered unlucky in Italy. When Renault exported the R17 to Italy, it was renamed R117.
• The year AD 117 or 117 BC.