# 117

This number is a composite.

117^{2} ± 2 are primes. [Russo]

117 can be written as the difference of prime squares (11^{2} - 2^{2}) or prime cubes (5^{3} - 2^{3}). [Sladcik]

117 = (1!_{2} + 1!_{2} + 7!_{2}) + (π(1)!_{2} + π(1)!_{2} + π(7)!_{2}).
Note that 117 is the only number with this property. [Firoozbakht]

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