31981055040 has 784 divisors, whose sum is σ = 126808845696. Its totient is φ = 7677711360.

The previous prime is 31981055023. The next prime is 31981055077. The reversal of 31981055040 is 4055018913.

31981055040 is a `hidden beast` number, since 3 + 1 + 98 + 10 + 550 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 31981054986 and 31981055004.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 310495629 + ... + 310495731.

Almost surely, 2^31981055040 is an apocalyptic number.

31981055040 is a gapful number since it is divisible by the number (30) 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 31981055040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63404422848).

31981055040 is an abundant number, since it is smaller than the sum of its proper divisors (94827790656).

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

31981055040 is an equidigital number, since it uses as much as digits as its factorization.

31981055040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The spelling of 31981055040 in words is "thirty-one billion, nine hundred eighty-one million, fifty-five thousand, forty".