31779972 has 96 divisors (see below), whose sum is σ = 95191040. Its totient is φ = 8981280.

The previous prime is 31779971. The next prime is 31779977. The reversal of 31779972 is 27997713.

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

It is not an unprimeable number, because it can be changed into a prime (31779971) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 95847 + ... + 96177.

Almost surely, 2^31779972 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 31779972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47595520).

31779972 is an abundant number, since it is smaller than the sum of its proper divisors (63411068).

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

31779972 is a wasteful number, since it uses less digits than its factorization.

31779972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 470 counting only the distinct ones).

The product of its digits is 166698, while the sum is 45.

The square root of 31779972 is about 5637.3727923564. The cubic root of 31779972 is about 316.7508848330.

The spelling of 31779972 in words is "thirty-one million, seven hundred seventy-nine thousand, nine hundred seventy-two".