31290812 has 36 divisors (see below), whose sum is σ = 67453344. Its totient is φ = 12620160.

The previous prime is 31290803. The next prime is 31290817. The reversal of 31290812 is 21809213.

It is a super-2 number, since 2×31290812² = 1958229831238688, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31290817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1364 + ... + 8027.

It is an arithmetic number, because the mean of its divisors is an integer number (1873704).

Almost surely, 2^31290812 is an apocalyptic number.

It is an amenable number.

31290812 is an abundant number, since it is smaller than the sum of its proper divisors (36162532).

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

31290812 is a wasteful number, since it uses less digits than its factorization.

31290812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9426 (or 9417 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 31290812 is about 5593.8190889588. The cubic root of 31290812 is about 315.1173225526.

The spelling of 31290812 in words is "thirty-one million, two hundred ninety thousand, eight hundred twelve".