31665972 has 24 divisors (see below), whose sum is σ = 79571296. Its totient is φ = 9743328.

The previous prime is 31665961. The next prime is 31666003. The reversal of 31665972 is 27956613.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 31665972.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 101338 + ... + 101649.

Almost surely, 2^31665972 is an apocalyptic number.

It is an amenable number.

31665972 is an abundant number, since it is smaller than the sum of its proper divisors (47905324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31665972 is a wasteful number, since it uses less digits than its factorization.

31665972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203007 (or 203005 counting only the distinct ones).

The product of its digits is 68040, while the sum is 39.

The square root of 31665972 is about 5627.2526156198. The cubic root of 31665972 is about 316.3716851686.

The spelling of 31665972 in words is "thirty-one million, six hundred sixty-five thousand, nine hundred seventy-two".