87
This number is a composite.
Single Curio View: (Seek other curios for this number)
87 is the largest number that yields a prime when any of
the one-digit primes 2, 5 or 7 is inserted between any two
digits. The only other such number is 27 (and trivially,
the 1 digit numbers). [Hasler]
Submitted: 2018-05-21 16:08:44; Last Modified: 2018-05-21 17:00:53.
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell