# 56

This number is a composite.

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

. (56, 58) is the only pair of successive double-digit even composite numbers m, n with composite reversals, R(m), R(n), such that m^4 + [R(m)]^4 and n^4 + [R(n)]^4, i.e., 56^4 + 65^4 and 58^4 + 85^4, are also primes. [Loungrides]

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