15

This number is a composite.

Just showing those entries submitted by 'Gupta': (Click here to show all)

+ !15 - 1 is prime. Note that !15 represents subfactorial 15. [Gupta]

+ There are only 15 invertible primes that consist of distinct digits. [Gupta]

Printed from the PrimePages <primes.utm.edu> © G. L. Honaker and Chris K. Caldwell