31890940 has 24 divisors (see below), whose sum is σ = 69132672. Its totient is φ = 12344640.

The previous prime is 31890919. The next prime is 31890959. The reversal of 31890940 is 4909813.

It is a junction number, because it is equal to n+sod(n) for n = 31890896 and 31890905.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 25099 + ... + 26338.

It is an arithmetic number, because the mean of its divisors is an integer number (2880528).

Almost surely, 2^31890940 is an apocalyptic number.

It is an amenable number.

31890940 is an abundant number, since it is smaller than the sum of its proper divisors (37241732).

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

31890940 is a wasteful number, since it uses less digits than its factorization.

31890940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51477 (or 51475 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 31890940 is about 5647.2063890033. The cubic root of 31890940 is about 317.1191291317.

The spelling of 31890940 in words is "thirty-one million, eight hundred ninety thousand, nine hundred forty".