33333...33333 (61-digits)

This number is a prime.

         3 3333333333 3322233332 5523333257 5233332552 3333222333 3333333333

+

    3 3 3 3 3
   3 3 3 3 3 3
  3 3 2 2 2 3 3
 3 3 2 5 5 2 3 3
3 3 2 5 7 5 2 3 3
 3 3 2 5 5 2 3 3
  3 3 2 2 2 3 3
   3 3 3 3 3 3
    3 3 3 3 3
The smallest centered hexagonal-congruent prime that contains all the prime digits. [Hartley]

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