9199

This number is a prime.

+ Define a "prime range digit sum (PRDS) prime" as a prime p equal to the sum of all the digits in the integers from 1 to n, for some n, with n also prime. There are only 9 PRDS primes less than 10000: 3, 433, 1801, 3331, 4159, 4519, 7039, 8821, and 9199. 9199 is the sum of the digits of the integers 1 to 757, and 757 is prime. [Keith]

Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell