21365213535756 has 24 divisors (see below), whose sum is σ = 55391294352240. Its totient is φ = 7121737845216.

The previous prime is 21365213535751. The next prime is 21365213535767. The reversal of 21365213535756 is 65753531256312.

21365213535756 is a `hidden beast` number, since 2 + 1 + 3 + 6 + 5 + 2 + 13 + 53 + 575 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (21365213535751) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98913025521 + ... + 98913025736.

It is an arithmetic number, because the mean of its divisors is an integer number (2307970598010).

Almost surely, 2^{21365213535756} is an apocalyptic number.

It is an amenable number.

21365213535756 is an abundant number, since it is smaller than the sum of its proper divisors (34026080816484).

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

21365213535756 is a wasteful number, since it uses less digits than its factorization.

21365213535756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197826051270 (or 197826051262 counting only the distinct ones).

The product of its digits is 17010000, while the sum is 54.

The spelling of 21365213535756 in words is "twenty-one trillion, three hundred sixty-five billion, two hundred thirteen million, five hundred thirty-five thousand, seven hundred fifty-six".