31971996 has 144 divisors (see below), whose sum is σ = 99147776. Its totient is φ = 8817984.

The previous prime is 31971977. The next prime is 31972009. The reversal of 31971996 is 69917913.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 251685 + ... + 251811.

Almost surely, 2^31971996 is an apocalyptic number.

31971996 is a gapful number since it is divisible by the number (36) 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 31971996, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49573888).

31971996 is an abundant number, since it is smaller than the sum of its proper divisors (67175780).

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

31971996 is a wasteful number, since it uses less digits than its factorization.

31971996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190 (or 176 counting only the distinct ones).

The product of its digits is 91854, while the sum is 45.

The square root of 31971996 is about 5654.3784804344. The cubic root of 31971996 is about 317.3875717419.

The spelling of 31971996 in words is "thirty-one million, nine hundred seventy-one thousand, nine hundred ninety-six".