31661972 has 12 divisors (see below), whose sum is σ = 55502580. Its totient is φ = 15804096.

The previous prime is 31661957. The next prime is 31661983. The reversal of 31661972 is 27916613.

It can be written as a sum of positive squares in 2 ways, for example, as 10995856 + 20666116 = 3316^2 + 4546^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3947 + ... + 8882.

It is an arithmetic number, because the mean of its divisors is an integer number (4625215).

Almost surely, 2^31661972 is an apocalyptic number.

It is an amenable number.

31661972 is a deficient number, since it is larger than the sum of its proper divisors (23840608).

31661972 is a wasteful number, since it uses less digits than its factorization.

31661972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13450 (or 13448 counting only the distinct ones).

The product of its digits is 13608, while the sum is 35.

The square root of 31661972 is about 5626.8971911703. The cubic root of 31661972 is about 316.3583634023.

The spelling of 31661972 in words is "thirty-one million, six hundred sixty-one thousand, nine hundred seventy-two".