68

This number is a composite.

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

+ 68 = -53+19+43+59. If -53 is considered to be a prime, then the sum of any three of these 4 primes is the square of a prime number; specifically the squares of the first 4 odd primes. [Rupinski]

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