75
(another Prime Pages' Curiosity)
Prime Curios!
Curios: Curios Search:
 
Participate:
+ 275 + 75 is prime. [Luhn]

+ 75 is the smallest non-prime deficient number whose sum as well as product of aliquot divisors is a perfect square. [Gupta]




Prime Curios! © 1999-2009 (all rights reserved)