691383957 has 16 divisors (see below), whose sum is σ = 1013966400. Its totient is φ = 419018160.

The previous prime is 691383923. The next prime is 691383977. The reversal of 691383957 is 759383196.

It is not a de Polignac number, because 691383957 - 2⁸ = 691383701 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691383907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 82582 + ... + 90567.

It is an arithmetic number, because the mean of its divisors is an integer number (63372900).

Almost surely, 2^691383957 is an apocalyptic number.

It is an amenable number.

691383957 is a deficient number, since it is larger than the sum of its proper divisors (322582443).

691383957 is a wasteful number, since it uses less digits than its factorization.

691383957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173185 (or 173163 counting only the distinct ones).

The product of its digits is 1224720, while the sum is 51.

The square root of 691383957 is about 26294.1810482852. The cubic root of 691383957 is about 884.2459906077.

The spelling of 691383957 in words is "six hundred ninety-one million, three hundred eighty-three thousand, nine hundred fifty-seven".