20564371338 has 64 divisors (see below), whose sum is σ = 47271831552. Its totient is φ = 5842180800.

The previous prime is 20564371259. The next prime is 20564371339. The reversal of 20564371338 is 83317346502.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 20564371338.

It is not an unprimeable number, because it can be changed into a prime (20564371339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7211613 + ... + 7214463.

It is an arithmetic number, because the mean of its divisors is an integer number (738622368).

Almost surely, 2^20564371338 is an apocalyptic number.

20564371338 is an abundant number, since it is smaller than the sum of its proper divisors (26707460214).

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

20564371338 is a wasteful number, since it uses less digits than its factorization.

20564371338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3779.

The product of its (nonzero) digits is 362880, while the sum is 42.

The spelling of 20564371338 in words is "twenty billion, five hundred sixty-four million, three hundred seventy-one thousand, three hundred thirty-eight".