11
This number is a prime.
Just showing those entries submitted by 'Harrison': (Click here to show all)
Sum of digits of the Mersenne prime exponent of M21701 equals 11. Probably the only time this will ever happen. [Harrison]
(There are 14 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