31928913 has 24 divisors (see below), whose sum is σ = 48409920. Its totient is φ = 20250720.

The previous prime is 31928881. The next prime is 31928927. The reversal of 31928913 is 31982913.

It is not a de Polignac number, because 31928913 - 2⁵ = 31928881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31928983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17670 + ... + 19392.

It is an arithmetic number, because the mean of its divisors is an integer number (2017080).

Almost surely, 2^31928913 is an apocalyptic number.

It is an amenable number.

31928913 is a deficient number, since it is larger than the sum of its proper divisors (16481007).

31928913 is a wasteful number, since it uses less digits than its factorization.

31928913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1829 (or 1826 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 31928913 is about 5650.5674936240. The cubic root of 31928913 is about 317.2449453075.

The spelling of 31928913 in words is "thirty-one million, nine hundred twenty-eight thousand, nine hundred thirteen".