72561806920 has 16 divisors (see below), whose sum is σ = 163264065660. Its totient is φ = 29024722752.

The previous prime is 72561806909. The next prime is 72561806923. The reversal of 72561806920 is 2960816527.

It can be written as a sum of positive squares in 2 ways, for example, as 72450335556 + 111471364 = 269166^2 + 10558^2 .

It is not an unprimeable number, because it can be changed into a prime (72561806923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 907022547 + ... + 907022626.

Almost surely, 2^72561806920 is an apocalyptic number.

It is an amenable number.

72561806920 is an abundant number, since it is smaller than the sum of its proper divisors (90702258740).

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

72561806920 is a wasteful number, since it uses less digits than its factorization.

72561806920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1814045184 (or 1814045180 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 46.

The spelling of 72561806920 in words is "seventy-two billion, five hundred sixty-one million, eight hundred six thousand, nine hundred twenty".