21769684785 has 24 divisors (see below), whose sum is σ = 37738596480. Its totient is φ = 11609121312.

The previous prime is 21769684693. The next prime is 21769684837. The reversal of 21769684785 is 58748696712.

21769684785 is a `hidden beast` number, since 2 + 1 + 76 + 96 + 8 + 478 + 5 = 666.

It is not a de Polignac number, because 21769684785 - 2⁹ = 21769684273 is a prime.

It is a Curzon 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, 438456 + ... + 485574.

It is an arithmetic number, because the mean of its divisors is an integer number (1572441520).

Almost surely, 2^21769684785 is an apocalyptic number.

It is an amenable number.

21769684785 is a deficient number, since it is larger than the sum of its proper divisors (15968911695).

21769684785 is a wasteful number, since it uses less digits than its factorization.

21769684785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57397 (or 57394 counting only the distinct ones).

The product of its digits is 40642560, while the sum is 63.

The spelling of 21769684785 in words is "twenty-one billion, seven hundred sixty-nine million, six hundred eighty-four thousand, seven hundred eighty-five".