31971984 has 80 divisors (see below), whose sum is σ = 94874880. Its totient is φ = 9175680.

The previous prime is 31971977. The next prime is 31972009. The reversal of 31971984 is 48917913.

It is a happy number.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8439 + ... + 11625.

It is an arithmetic number, because the mean of its divisors is an integer number (1185936).

Almost surely, 2^31971984 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31971984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47437440).

31971984 is an abundant number, since it is smaller than the sum of its proper divisors (62902896).

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

31971984 is a wasteful number, since it uses less digits than its factorization.

31971984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3228 (or 3222 counting only the distinct ones).

The product of its digits is 54432, while the sum is 42.

The square root of 31971984 is about 5654.3774193098. The cubic root of 31971984 is about 317.3875320337.

The spelling of 31971984 in words is "thirty-one million, nine hundred seventy-one thousand, nine hundred eighty-four".