20809517769684 has 108 divisors (see below), whose sum is σ = 63163759171968. Its totient is φ = 5753783700000.

The previous prime is 20809517769637. The next prime is 20809517769713. The reversal of 20809517769684 is 48696771590802.

20809517769684 is a `hidden beast` number, since 20 + 8 + 0 + 9 + 517 + 7 + 6 + 9 + 6 + 84 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 190215942 + ... + 190325309.

Almost surely, 2^{20809517769684} is an apocalyptic number.

It is an amenable number.

20809517769684 is an abundant number, since it is smaller than the sum of its proper divisors (42354241402284).

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

20809517769684 is a wasteful number, since it uses less digits than its factorization.

20809517769684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380541306 (or 380541294 counting only the distinct ones).

The product of its (nonzero) digits is 365783040, while the sum is 72.

The spelling of 20809517769684 in words is "twenty trillion, eight hundred nine billion, five hundred seventeen million, seven hundred sixty-nine thousand, six hundred eighty-four".