This number is a prime.
The diagonals of a regular 24-gon intersect at 7297 internal points (6144 intersections of two diagonals, 864 of three, 264 of four, 24 of five, and one intersection of twelve diagonals). [Caldwell]
The smallest emirp that remains an emirp when each digit is repeated a number of times equal to its complement: 777222222229777. [Beedassy]
(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