1732565537257
This number is a prime.
173 2565537257
The smallest concatenate emirp using all the known primes p of the form 2^n+1 (p = 2, 3, 5, 17, 257, 65537). [Loungrides]
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell