31083920 has 80 divisors (see below), whose sum is σ = 84423168. Its totient is φ = 10421760.

The previous prime is 31083919. The next prime is 31083929. The reversal of 31083920 is 2938013.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 31083920.

It is not an unprimeable number, because it can be changed into a prime (31083929) 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, 25730 + ... + 26910.

Almost surely, 2^31083920 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 31083920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42211584).

31083920 is an abundant number, since it is smaller than the sum of its proper divisors (53339248).

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

31083920 is a wasteful number, since it uses less digits than its factorization.

31083920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248 (or 1242 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 31083920 is about 5575.2955078632. The cubic root of 31083920 is about 314.4212772130.

The spelling of 31083920 in words is "thirty-one million, eighty-three thousand, nine hundred twenty".