1663
This number is a prime.
A prime p such that 4p + 7 is prime. [Russo]
The smallest prime number for which the sum of the
reciprocals of its digits equals the sum of the reciprocals
of the digits of its prime index (261). [Gaydos]
(There is one curio for this number that has not yet been approved by an editor.)
Printed from the PrimePages <primes.utm.edu> © G. L. Honaker and Chris K. Caldwell