20564542464 has 88 divisors (see below), whose sum is σ = 54882853920. Its totient is φ = 6845988864.

The previous prime is 20564542459. The next prime is 20564542483. The reversal of 20564542464 is 46424546502.

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, 2634952 + ... + 2642744.

Almost surely, 2^20564542464 is an apocalyptic number.

20564542464 is a gapful number since it is divisible by the number (24) 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 20564542464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27441426960).

20564542464 is an abundant number, since it is smaller than the sum of its proper divisors (34318311456).

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

20564542464 is an equidigital number, since it uses as much as digits as its factorization.

20564542464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8675 (or 8657 counting only the distinct ones).

The product of its (nonzero) digits is 921600, while the sum is 42.

The spelling of 20564542464 in words is "twenty billion, five hundred sixty-four million, five hundred forty-two thousand, four hundred sixty-four".