31581107872 has 96 divisors (see below), whose sum is σ = 64521651600. Its totient is φ = 15204630528.

The previous prime is 31581107837. The next prime is 31581107891. The reversal of 31581107872 is 27870118513.

It can be written as a sum of positive squares in 8 ways, for example, as 15877008016 + 15704099856 = 126004^2 + 125316^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72935368 + ... + 72935800.

Almost surely, 2^31581107872 is an apocalyptic number.

31581107872 is a gapful number since it is divisible by the number (32) 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 31581107872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32260825800).

31581107872 is an abundant number, since it is smaller than the sum of its proper divisors (32940543728).

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

31581107872 is a wasteful number, since it uses less digits than its factorization.

31581107872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 978 (or 970 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 43.

The spelling of 31581107872 in words is "thirty-one billion, five hundred eighty-one million, one hundred seven thousand, eight hundred seventy-two".