20645818764 has 24 divisors (see below), whose sum is σ = 48182257200. Its totient is φ = 6880699584.

The previous prime is 20645818723. The next prime is 20645818799. The reversal of 20645818764 is 46781854602.

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, 84339 + ... + 220010.

It is an arithmetic number, because the mean of its divisors is an integer number (2007594050).

Almost surely, 2^20645818764 is an apocalyptic number.

It is an amenable number.

20645818764 is an abundant number, since it is smaller than the sum of its proper divisors (27536438436).

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

20645818764 is a wasteful number, since it uses less digits than its factorization.

20645818764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310009 (or 310007 counting only the distinct ones).

The product of its (nonzero) digits is 2580480, while the sum is 51.

The spelling of 20645818764 in words is "twenty billion, six hundred forty-five million, eight hundred eighteen thousand, seven hundred sixty-four".