31161980 has 12 divisors (see below), whose sum is σ = 65440200. Its totient is φ = 12464784.

The previous prime is 31161961. The next prime is 31161983. The reversal of 31161980 is 8916113.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31161983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 779030 + ... + 779069.

It is an arithmetic number, because the mean of its divisors is an integer number (5453350).

Almost surely, 2^31161980 is an apocalyptic number.

It is an amenable number.

31161980 is an abundant number, since it is smaller than the sum of its proper divisors (34278220).

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

31161980 is a wasteful number, since it uses less digits than its factorization.

31161980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1558108 (or 1558106 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 31161980 is about 5582.2916441189. The cubic root of 31161980 is about 314.6842557159.

The spelling of 31161980 in words is "thirty-one million, one hundred sixty-one thousand, nine hundred eighty".