31121992 has 32 divisors (see below), whose sum is σ = 63957600. Its totient is φ = 14080000.

The previous prime is 31121989. The next prime is 31121999. The reversal of 31121992 is 29912113.

It is a self number, because there is not a number n which added to its sum of digits gives 31121992.

It is not an unprimeable number, because it can be changed into a prime (31121999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21384 + ... + 22792.

It is an arithmetic number, because the mean of its divisors is an integer number (1998675).

Almost surely, 2^31121992 is an apocalyptic number.

It is an amenable number.

31121992 is an abundant number, since it is smaller than the sum of its proper divisors (32835608).

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

31121992 is a wasteful number, since it uses less digits than its factorization.

31121992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1677 (or 1673 counting only the distinct ones).

The product of its digits is 972, while the sum is 28.

The square root of 31121992 is about 5578.7088111856. The cubic root of 31121992 is about 314.5495939645.

The spelling of 31121992 in words is "thirty-one million, one hundred twenty-one thousand, nine hundred ninety-two".