31561972 has 12 divisors (see below), whose sum is σ = 59482276. Its totient is φ = 14567040.

The previous prime is 31561969. The next prime is 31561973. The reversal of 31561972 is 27916513.

It can be written as a sum of positive squares in 2 ways, for example, as 9696996 + 21864976 = 3114^2 + 4676^2 .

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31561973) by changing a digit.

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, 303429 + ... + 303532.

Almost surely, 2^31561972 is an apocalyptic number.

It is an amenable number.

31561972 is a deficient number, since it is larger than the sum of its proper divisors (27920304).

31561972 is a wasteful number, since it uses less digits than its factorization.

31561972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 606978 (or 606976 counting only the distinct ones).

The product of its digits is 11340, while the sum is 34.

The square root of 31561972 is about 5618.0042719813. The cubic root of 31561972 is about 316.0249539659.

The spelling of 31561972 in words is "thirty-one million, five hundred sixty-one thousand, nine hundred seventy-two".