31312940 has 24 divisors (see below), whose sum is σ = 65871792. Its totient is φ = 12503360.

The previous prime is 31312937. The next prime is 31312949. The reversal of 31312940 is 4921313.

It is a super-2 number, since 2×31312940² = 1961000422887200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31312949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15467 + ... + 17373.

It is an arithmetic number, because the mean of its divisors is an integer number (2744658).

Almost surely, 2^31312940 is an apocalyptic number.

It is an amenable number.

31312940 is an abundant number, since it is smaller than the sum of its proper divisors (34558852).

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

31312940 is a wasteful number, since it uses less digits than its factorization.

31312940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2737 (or 2735 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 31312940 is about 5595.7966367623. The cubic root of 31312940 is about 315.1915858121.

The spelling of 31312940 in words is "thirty-one million, three hundred twelve thousand, nine hundred forty".