74

This number is a composite.

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

+ The only double-digit number ab such that (ab)^a-(ba)^b is prime, i.e., 74^7-47^4 = 12151275393343 that is a prime. [Loungrides]

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