608191
This number is a prime.
608191 inverted (161809) becomes the smallest 2-sphenic number whose concatenation of prime factors (43 × 53 × 71) create four primes, i.e., 435371, 437153, 534371, 537143. Can you find another such prime? [Loungrides]
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell