31687716 has 12 divisors (see below), whose sum is σ = 73938032. Its totient is φ = 10562568.

The previous prime is 31687709. The next prime is 31687727. The reversal of 31687716 is 61778613.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×31687716² = 2008222690593312, which contains 22 as substring.

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, 1320310 + ... + 1320333.

Almost surely, 2^31687716 is an apocalyptic number.

It is an amenable number.

31687716 is an abundant number, since it is smaller than the sum of its proper divisors (42250316).

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

31687716 is a wasteful number, since it uses less digits than its factorization.

31687716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2640650 (or 2640648 counting only the distinct ones).

The product of its digits is 42336, while the sum is 39.

The square root of 31687716 is about 5629.1843103597. The cubic root of 31687716 is about 316.4440826720. Note that the first 3 decimals are identical.

The spelling of 31687716 in words is "thirty-one million, six hundred eighty-seven thousand, seven hundred sixteen".