4153
This number is a prime.
The smaller of only two primes concatenated in ascending order from two consecutive Pythagorean double-digit primes. The other one is 6173. [Loungrides]
(There is one curio for this number that has not yet been approved by an editor.)
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell