31972257 has 24 divisors (see below), whose sum is σ = 49406760. Its totient is φ = 19852800.

The previous prime is 31972229. The next prime is 31972273. The reversal of 31972257 is 75227913.

It can be written as a sum of positive squares in 4 ways, for example, as 11532816 + 20439441 = 3396^2 + 4521^2 .

It is not a de Polignac number, because 31972257 - 2²³ = 23583649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31972217) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14419 + ... + 16487.

It is an arithmetic number, because the mean of its divisors is an integer number (2058615).

Almost surely, 2^31972257 is an apocalyptic number.

It is an amenable number.

31972257 is a deficient number, since it is larger than the sum of its proper divisors (17434503).

31972257 is a wasteful number, since it uses less digits than its factorization.

31972257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2193 (or 2190 counting only the distinct ones).

The product of its digits is 26460, while the sum is 36.

The square root of 31972257 is about 5654.4015598470. The cubic root of 31972257 is about 317.3884353928.

The spelling of 31972257 in words is "thirty-one million, nine hundred seventy-two thousand, two hundred fifty-seven".