31513500020 has 24 divisors (see below), whose sum is σ = 67427000424. Its totient is φ = 12367561856.

The previous prime is 31513499987. The next prime is 31513500037. The reversal of 31513500020 is 2000531513.

It can be written as a sum of positive squares in 4 ways, for example, as 4125235984 + 27388264036 = 64228^2 + 165494^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 31513499965 and 31513500001.

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, 14863799 + ... + 14865918.

It is an arithmetic number, because the mean of its divisors is an integer number (2809458351).

Almost surely, 2^31513500020 is an apocalyptic number.

It is an amenable number.

31513500020 is an abundant number, since it is smaller than the sum of its proper divisors (35913500404).

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

31513500020 is a wasteful number, since it uses less digits than its factorization.

31513500020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29729779 (or 29729777 counting only the distinct ones).

The product of its (nonzero) digits is 450, while the sum is 20.

The spelling of 31513500020 in words is "thirty-one billion, five hundred thirteen million, five hundred thousand, twenty".