31217972 has 12 divisors (see below), whose sum is σ = 54670980. Its totient is φ = 15597696.

The previous prime is 31217959. The next prime is 31217983. The reversal of 31217972 is 27971213.

It can be written as a sum of positive squares in 2 ways, for example, as 21939856 + 9278116 = 4684^2 + 3046^2 .

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8054 + ... + 11282.

It is an arithmetic number, because the mean of its divisors is an integer number (4555915).

Almost surely, 2^31217972 is an apocalyptic number.

It is an amenable number.

31217972 is a deficient number, since it is larger than the sum of its proper divisors (23453008).

31217972 is a wasteful number, since it uses less digits than its factorization.

31217972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5650 (or 5648 counting only the distinct ones).

The product of its digits is 5292, while the sum is 32.

The square root of 31217972 is about 5587.3045379682. The cubic root of 31217972 is about 314.8726183536.

The spelling of 31217972 in words is "thirty-one million, two hundred seventeen thousand, nine hundred seventy-two".