31921113 has 16 divisors (see below), whose sum is σ = 48746880. Its totient is φ = 18201216.

The previous prime is 31921111. The next prime is 31921129. The reversal of 31921113 is 31112913.

It is not a de Polignac number, because 31921113 - 2¹ = 31921111 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 31921113.

It is not an unprimeable number, because it can be changed into a prime (31921111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10333 + ... + 13061.

It is an arithmetic number, because the mean of its divisors is an integer number (3046680).

Almost surely, 2^31921113 is an apocalyptic number.

It is an amenable number.

31921113 is a deficient number, since it is larger than the sum of its proper divisors (16825767).

31921113 is a wasteful number, since it uses less digits than its factorization.

31921113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3296.

The product of its digits is 162, while the sum is 21.

The square root of 31921113 is about 5649.8772553039. The cubic root of 31921113 is about 317.2191096633.

The spelling of 31921113 in words is "thirty-one million, nine hundred twenty-one thousand, one hundred thirteen".