9551

This number is a prime.

Compare 9551 with the 9551st prime. [Punches]

The largest prime found in the following array:

 9 1 3 3
 1 5 8 3
 7 5 2 9
 3 9 1 1.

Every row, column, and main diagonal is a different emirp. Ignoring rotations, it is the only possible 4-by-4 prime magic square of this type.

The smallest prime with a perfect square gap from both its previous prime and next prime, i.e., 9551 - 2² is its previous prime and 9551 + 6² is its next prime. [Gudipati]