31871864 has 8 divisors (see below), whose sum is σ = 59759760. Its totient is φ = 15935928.

The previous prime is 31871857. The next prime is 31871869. The reversal of 31871864 is 46817813.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31871869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1991984 + ... + 1991999.

It is an arithmetic number, because the mean of its divisors is an integer number (7469970).

Almost surely, 2^31871864 is an apocalyptic number.

It is an amenable number.

31871864 is a deficient number, since it is larger than the sum of its proper divisors (27887896).

31871864 is a wasteful number, since it uses less digits than its factorization.

31871864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3983989 (or 3983985 counting only the distinct ones).

The product of its digits is 32256, while the sum is 38.

The square root of 31871864 is about 5645.5171596586. The cubic root of 31871864 is about 317.0558868119.

The spelling of 31871864 in words is "thirty-one million, eight hundred seventy-one thousand, eight hundred sixty-four".