20320564056 has 96 divisors (see below), whose sum is σ = 55159128000. Its totient is φ = 6235512192.

The previous prime is 20320564039. The next prime is 20320564079. The reversal of 20320564056 is 65046502302.

It is a super-2 number, since 2×20320564056² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1530615 + ... + 1543833.

It is an arithmetic number, because the mean of its divisors is an integer number (574574250).

Almost surely, 2^20320564056 is an apocalyptic number.

20320564056 is a gapful number since it is divisible by the number (26) 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 20320564056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27579564000).

20320564056 is an abundant number, since it is smaller than the sum of its proper divisors (34838563944).

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

20320564056 is a wasteful number, since it uses less digits than its factorization.

20320564056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13633 (or 13616 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 33.

The spelling of 20320564056 in words is "twenty billion, three hundred twenty million, five hundred sixty-four thousand, fifty-six".