21757685877 has 12 divisors (see below), whose sum is σ = 31485230400. Its totient is φ = 14478603048.

The previous prime is 21757685857. The next prime is 21757685879. The reversal of 21757685877 is 77858675712.

21757685877 is a `hidden beast` number, since 2 + 1 + 7 + 576 + 8 + 58 + 7 + 7 = 666.

It is not a de Polignac number, because 21757685877 - 2¹⁵ = 21757653109 is a prime.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21757685879) 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, 2204877 + ... + 2214722.

It is an arithmetic number, because the mean of its divisors is an integer number (2623769200).

Almost surely, 2^21757685877 is an apocalyptic number.

It is an amenable number.

21757685877 is a deficient number, since it is larger than the sum of its proper divisors (9727544523).

21757685877 is a wasteful number, since it uses less digits than its factorization.

21757685877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4420152 (or 4420149 counting only the distinct ones).

The product of its digits is 46099200, while the sum is 63.

The spelling of 21757685877 in words is "twenty-one billion, seven hundred fifty-seven million, six hundred eighty-five thousand, eight hundred seventy-seven".