31331312 has 20 divisors (see below), whose sum is σ = 61275096. Its totient is φ = 15518400.

The previous prime is 31331303. The next prime is 31331317. The reversal of 31331312 is 21313313.

It is a super-2 number, since 2×31331312² = 1963302223282688, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31331317) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7439 + ... + 10862.

Almost surely, 2^31331312 is an apocalyptic number.

It is an amenable number.

31331312 is a deficient number, since it is larger than the sum of its proper divisors (29943784).

31331312 is a wasteful number, since it uses less digits than its factorization.

31331312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18416 (or 18410 counting only the distinct ones).

The product of its digits is 162, while the sum is 17.

The square root of 31331312 is about 5597.4379853644. The cubic root of 31331312 is about 315.2532170704.

Adding to 31331312 its reverse (21313313), we get a palindrome (52644625).

The spelling of 31331312 in words is "thirty-one million, three hundred thirty-one thousand, three hundred twelve".