21856850186740 has 24 divisors (see below), whose sum is σ = 46305574648200. Its totient is φ = 8665370692608.

The previous prime is 21856850186737. The next prime is 21856850186849. The reversal of 21856850186740 is 4768105865812.

It can be written as a sum of positive squares in 4 ways, for example, as 666424057104 + 21190426129636 = 816348^2 + 4603306^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4835584065 + ... + 4835588584.

It is an arithmetic number, because the mean of its divisors is an integer number (1929398943675).

Almost surely, 2^{21856850186740} is an apocalyptic number.

21856850186740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21856850186740 is an abundant number, since it is smaller than the sum of its proper divisors (24448724461460).

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

21856850186740 is a wasteful number, since it uses less digits than its factorization.

21856850186740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9671172771 (or 9671172769 counting only the distinct ones).

The product of its (nonzero) digits is 25804800, while the sum is 61.

The spelling of 21856850186740 in words is "twenty-one trillion, eight hundred fifty-six billion, eight hundred fifty million, one hundred eighty-six thousand, seven hundred forty".