21856485877 has 16 divisors (see below), whose sum is σ = 22365486720. Its totient is φ = 21354522112.

The previous prime is 21856485857. The next prime is 21856485919. The reversal of 21856485877 is 77858465812.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21856485877 - 2¹¹ = 21856483829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21856485857) 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, 3486648 + ... + 3492910.

It is an arithmetic number, because the mean of its divisors is an integer number (1397842920).

Almost surely, 2^21856485877 is an apocalyptic number.

It is an amenable number.

21856485877 is a deficient number, since it is larger than the sum of its proper divisors (509000843).

21856485877 is a wasteful number, since it uses less digits than its factorization.

21856485877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6812.

The product of its digits is 30105600, while the sum is 61.

The spelling of 21856485877 in words is "twenty-one billion, eight hundred fifty-six million, four hundred eighty-five thousand, eight hundred seventy-seven".