21162105765 has 96 divisors (see below), whose sum is σ = 41063742720. Its totient is φ = 10423074816.

The previous prime is 21162105751. The next prime is 21162105773. The reversal of 21162105765 is 56750126112.

21162105765 is a `hidden beast` number, since 2 + 11 + 62 + 10 + 576 + 5 = 666.

It is not a de Polignac number, because 21162105765 - 2⁴ = 21162105749 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 797349 + ... + 823461.

It is an arithmetic number, because the mean of its divisors is an integer number (427747320).

Almost surely, 2^21162105765 is an apocalyptic number.

It is an amenable number.

21162105765 is a deficient number, since it is larger than the sum of its proper divisors (19901636955).

21162105765 is a wasteful number, since it uses less digits than its factorization.

21162105765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26185 (or 26173 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The spelling of 21162105765 in words is "twenty-one billion, one hundred sixty-two million, one hundred five thousand, seven hundred sixty-five".