31997457 has 16 divisors (see below), whose sum is σ = 47494080. Its totient is φ = 21290976.

The previous prime is 31997431. The next prime is 31997473. The reversal of 31997457 is 75479913.

31997457 is a `hidden beast` number, since 3 + 199 + 7 + 457 = 666.

It is not a de Polignac number, because 31997457 - 2⁸ = 31997201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31997477) 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, 21613 + ... + 23045.

It is an arithmetic number, because the mean of its divisors is an integer number (2968380).

Almost surely, 2^31997457 is an apocalyptic number.

It is an amenable number.

31997457 is a deficient number, since it is larger than the sum of its proper divisors (15496623).

31997457 is a wasteful number, since it uses less digits than its factorization.

31997457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2269 (or 2263 counting only the distinct ones).

The product of its digits is 238140, while the sum is 45.

The square root of 31997457 is about 5656.6294734586. The cubic root of 31997457 is about 317.4718002524.

The spelling of 31997457 in words is "thirty-one million, nine hundred ninety-seven thousand, four hundred fifty-seven".