20807891568 has 60 divisors (see below), whose sum is σ = 58313590608. Its totient is φ = 6926388480.

The previous prime is 20807891563. The next prime is 20807891623. The reversal of 20807891568 is 86519870802.

20807891568 is a `hidden beast` number, since 2 + 0 + 8 + 0 + 78 + 9 + 1 + 568 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20807891563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5308 + ... + 204068.

Almost surely, 2^20807891568 is an apocalyptic number.

It is an amenable number.

20807891568 is an abundant number, since it is smaller than the sum of its proper divisors (37505699040).

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

20807891568 is a wasteful number, since it uses less digits than its factorization.

20807891568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199502 (or 199493 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 54.

The spelling of 20807891568 in words is "twenty billion, eight hundred seven million, eight hundred ninety-one thousand, five hundred sixty-eight".