177

One hundred and seventy-seven is the ninth Leyland number, where 177 = 2 7 + 7 2 . {\displaystyle 177=2^{7}+7^{2}.} The fifty-seventh semiprime is 177 (after the square of 13), and it is the fifty-first semiprime with distinct prime factors. The magic constant M {\displaystyle M} of the smallest full 3 × 3 {\displaystyle 3\times 3} magic square consisting of distinct primes is 177