# 137438953481

This number is a prime.

13 7438953481

Bertrand's postulate implies that there are infinitely many
numbers *a* for which floor(2^{a}),
floor(2^{2a}),
floor(2^{22a}), ...
are all prime. The smallest of these is
*a* = 1.25164 75977 90463 01759 44320 53623... and
generates the Bertrand primes: 2, 5, 37,
137438953481, .... The next Bertrand prime has 41,373,247,571
digits. [Caldwell]

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