3719

This number is a prime.

Consider four ending digits of prime numbers, i.e., {1, 3, 7, 9}. The permutation {3, 7, 1, 9} occurs at 53, where the distinct frequencies of each of the four ending digits less than or equal to 53 can be written (high-to-low) as "3719", i.e., there are five 3s, four 7s, three 1s, two 9s. Question: At what prime p can we say that all 24 permutations of the ending digits have occurred? The sequence of primes leading to a solution begins 53, 239, 347, ... , corresponding to the first occurrence of {3, 7, 1 ,9}, {3, 7, 9, 1}, {7, 3, 1, 9}, etc. (See OEIS A390417)