284
This number is a composite.
The product of the factorial and primorial of 284 minus one is prime. I.e., 284!*284#-1 is prime. [Opao]
The only known amicable number with three prime factors. Dedicated to G. L. Honaker, Jr. on his 2*8*4 = 82 = 64-th birthday (Square Root Day 5/5/25). [Gupta]
Printed from the PrimePages <t5k.org> © G. L. Honaker and Reginald McLean