31130920 has 64 divisors (see below), whose sum is σ = 74131200. Its totient is φ = 11746560.

The previous prime is 31130903. The next prime is 31130929. The reversal of 31130920 is 2903113.

It is not an unprimeable number, because it can be changed into a prime (31130929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54235 + ... + 54805.

It is an arithmetic number, because the mean of its divisors is an integer number (1158300).

Almost surely, 2^31130920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31130920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37065600).

31130920 is an abundant number, since it is smaller than the sum of its proper divisors (43000280).

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

31130920 is a wasteful number, since it uses less digits than its factorization.

31130920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658 (or 654 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 19.

The square root of 31130920 is about 5579.5089389659. The cubic root of 31130920 is about 314.5796694845.

The spelling of 31130920 in words is "thirty-one million, one hundred thirty thousand, nine hundred twenty".