31990656 has 64 divisors (see below), whose sum is σ = 85582080. Its totient is φ = 10587648.

The previous prime is 31990649. The next prime is 31990669. The reversal of 31990656 is 65609913.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 86985 + ... + 87351.

It is an arithmetic number, because the mean of its divisors is an integer number (1337220).

Almost surely, 2^31990656 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 31990656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42791040).

31990656 is an abundant number, since it is smaller than the sum of its proper divisors (53591424).

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

31990656 is a wasteful number, since it uses less digits than its factorization.

31990656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611 (or 599 counting only the distinct ones).

The product of its (nonzero) digits is 43740, while the sum is 39.

The square root of 31990656 is about 5656.0282884724. The cubic root of 31990656 is about 317.4493059783.

The spelling of 31990656 in words is "thirty-one million, nine hundred ninety thousand, six hundred fifty-six".