31561924 has 15 divisors (see below), whose sum is σ = 56295547. Its totient is φ = 15483208.

The previous prime is 31561919. The next prime is 31561927. The reversal of 31561924 is 42916513.

The square root of 31561924 is 5618.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 6160324 + 25401600 = 2482^2 + 5040^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=4, B=53.

It is a Duffinian number.

Its product of digits (6480) is a multiple of the sum of its prime factors (216).

It is not an unprimeable number, because it can be changed into a prime (31561927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 4 ways as a sum of consecutive naturals, for example, 595482 + ... + 595534.

Almost surely, 2^31561924 is an apocalyptic number.

31561924 is the 5618-th square number.

It is an amenable number.

31561924 is a deficient number, since it is larger than the sum of its proper divisors (24733623).

31561924 is an frugal number, since it uses more digits than its factorization.

31561924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216 (or 55 counting only the distinct ones).

The product of its digits is 6480, while the sum is 31.

The cubic root of 31561924 is about 316.0247937604.

The spelling of 31561924 in words is "thirty-one million, five hundred sixty-one thousand, nine hundred twenty-four".