This number is a prime.

+ The smallest odd prime number that produces two triangular numbers (4186 and 3160) when its prime index (513) is subtracted from it or added to it. The next such prime is 2955107. [Gaydos]

(There are 2 curios for this number that have not yet been approved by an editor.)

Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell