19
This number is a prime.
Just showing those entries submitted by 'Caldwell': (Click here to show all)
The decimal expansion of 1919 begins with the digits 19. This is not true for pp, where p is any other prime less than 19,000,000,019. [Caldwell]
19 is the |1 - 9|th prime number. [Caldwell]
19^0 + 19^1 + ... + 19^18 (19 terms) is prime. [Caldwell]
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell