597

597 = 3 x 199.

597 to 611 is the largest gap between two consecutive semiprimes (having exactly two prime factors) less than 1000. It is the smallest semiprime such that gap between it and the next semiprime is 14 (A131109).

597 is a value of n for which n!!! + 1 is prime (A037083).

597 is 4342 in base 5 and 212 in base 17. 597 contains only the digits 1 and 2 in base 4 (21111) (A032925) and base 17.

597² = 356,409 contains exactly six different digits (A054034).

58! begins with the digits 597. 58 is the smallest integer m such that m! begins with 597 (A076219).

Source: Prime Curios!