31981880 has 32 divisors (see below), whose sum is σ = 82239840. Its totient is φ = 10965120.

The previous prime is 31981877. The next prime is 31981889. The reversal of 31981880 is 8818913.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31981889) 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, 56831 + ... + 57390.

It is an arithmetic number, because the mean of its divisors is an integer number (2569995).

Almost surely, 2^31981880 is an apocalyptic number.

It is an amenable number.

31981880 is an abundant number, since it is smaller than the sum of its proper divisors (50257960).

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

31981880 is a wasteful number, since it uses less digits than its factorization.

31981880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114239 (or 114235 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 38.

The square root of 31981880 is about 5655.2524258427. The cubic root of 31981880 is about 317.4202746896.

The spelling of 31981880 in words is "thirty-one million, nine hundred eighty-one thousand, eight hundred eighty".