68927
This number is a prime.
68927 is the largest known prime that remains prime after its insertion into all internal positions (one at a time):
6'68927'8927, 68'68927'927, 689'68927'27 and 6892'68927'7. [Rivera]
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell