2663
This number is a prime.
The least integer such that the sum of its digits in every base B = 2, 3, 4, 5, ... 13 is prime. [Crespi de Valldaura]
The number of digits in the twentieth perfect number can be expressed as 14^3-3^4 or 2663. [Leonardis]
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell