Migration complete - please let us know if anything isn't working.
This number is a composite.
278*2^566-1 is prime. Note that 2+7+8 = 5+6+6.
(There are 4 curios for this number that have not yet been approved by an editor.)
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell