9137
This number is a prime.
The largest diagonal prime of order 2 with distinct digits. (A diagonal prime is a prime of n2 digits (n > 1) arranged left-right, top-down, in a n-by-n matrix, where the diagonals are also prime in each direction). [Loungrides]
If we examine the possible end digits of the first ten
million primes, then "9" occurs the least, followed by "1",
then "3", with "7" occurring the most. [Gupta]
The last known term corresponding to a(1)-a(19) in OEIS A390417. The sequence begins 3719, 3791, 7319, 7391, 7931, 7913, 3179, 3971, 7139, 9731, 3917, 3197, 9371, 1739, 1379,
7193, 1397, 9317, 9137. [Keith]
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