31912920 has 128 divisors (see below), whose sum is σ = 114609600. Its totient is φ = 7852032.

The previous prime is 31912901. The next prime is 31912921. The reversal of 31912920 is 2921913.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31912921) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12904 + ... + 15176.

Almost surely, 2^31912920 is an apocalyptic number.

31912920 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31912920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57304800).

31912920 is an abundant number, since it is smaller than the sum of its proper divisors (82696680).

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

31912920 is a wasteful number, since it uses less digits than its factorization.

31912920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2306 (or 2296 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 31912920 is about 5649.1521487742. The cubic root of 31912920 is about 317.1919677677.

The spelling of 31912920 in words is "thirty-one million, nine hundred twelve thousand, nine hundred twenty".