21756361320 has 128 divisors (see below), whose sum is σ = 76787222400. Its totient is φ = 5460415488.

The previous prime is 21756361307. The next prime is 21756361409. The reversal of 21756361320 is 2316365712.

21756361320 is a `hidden beast` number, since 2 + 1 + 7 + 5 + 636 + 13 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 574134 + ... + 610853.

It is an arithmetic number, because the mean of its divisors is an integer number (599900175).

Almost surely, 2^21756361320 is an apocalyptic number.

21756361320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21756361320 is an abundant number, since it is smaller than the sum of its proper divisors (55030861080).

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

21756361320 is a wasteful number, since it uses less digits than its factorization.

21756361320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1185024 (or 1185014 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

The spelling of 21756361320 in words is "twenty-one billion, seven hundred fifty-six million, three hundred sixty-one thousand, three hundred twenty".