1230507001

This number is a prime.

Just showing those entries submitted by 'Murthy': (Click here to show all)

+ Write digits from 2 to 9. Replace the composite digits by a 0. Sandwitch the number between two 1's. The resulting number is a prime. Its digit reversal is also a prime. [Murthy]

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