31909968 has 120 divisors (see below), whose sum is σ = 95752800. Its totient is φ = 9891072.

The previous prime is 31909961. The next prime is 31909991. The reversal of 31909968 is 86990913.

It is a super-2 number, since 2×31909968² = 2036492115522048, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31909961) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 292698 + ... + 292806.

It is an arithmetic number, because the mean of its divisors is an integer number (797940).

Almost surely, 2^31909968 is an apocalyptic number.

31909968 is a gapful number since it is divisible by the number (38) 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 31909968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47876400).

31909968 is an abundant number, since it is smaller than the sum of its proper divisors (63842832).

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

31909968 is a wasteful number, since it uses less digits than its factorization.

31909968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249 (or 240 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 31909968 is about 5648.8908645857. The cubic root of 31909968 is about 317.1821871986.

The spelling of 31909968 in words is "thirty-one million, nine hundred nine thousand, nine hundred sixty-eight".