1234567
This number is a composite.
The prime factors of 1234567 (127 * 9721) form a peak-palindromic arrangement of digits (1279721). It is curious that the prime factors of 1279721 are all three emirps (79 * 97 * 167) which upon concatenation form yet another prime (7997167). [Trotter]
(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