20999761564776 has 64 divisors (see below), whose sum is σ = 55057273344000. Its totient is φ = 6661930004928.

The previous prime is 20999761564723. The next prime is 20999761564777. The reversal of 20999761564776 is 67746516799902.

It is not an unprimeable number, because it can be changed into a prime (20999761564777) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 95475696 + ... + 95695391.

It is an arithmetic number, because the mean of its divisors is an integer number (860269896000).

Almost surely, 2^{20999761564776} is an apocalyptic number.

It is an amenable number.

20999761564776 is an abundant number, since it is smaller than the sum of its proper divisors (34057511779224).

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

20999761564776 is a wasteful number, since it uses less digits than its factorization.

20999761564776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191171318 (or 191171314 counting only the distinct ones).

The product of its (nonzero) digits is 2160406080, while the sum is 78.

The spelling of 20999761564776 in words is "twenty trillion, nine hundred ninety-nine billion, seven hundred sixty-one million, five hundred sixty-four thousand, seven hundred seventy-six".