21365564716356 has 96 divisors (see below), whose sum is σ = 60139648235520. Its totient is φ = 5783160218400.

The previous prime is 21365564716351. The next prime is 21365564716403. The reversal of 21365564716356 is 65361746556312.

It is a self number, because there is not a number n which added to its sum of digits gives 21365564716356.

It is not an unprimeable number, because it can be changed into a prime (21365564716351) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 17965320 + ... + 19117631.

It is an arithmetic number, because the mean of its divisors is an integer number (626454669120).

Almost surely, 2^{21365564716356} is an apocalyptic number.

It is an amenable number.

21365564716356 is an abundant number, since it is smaller than the sum of its proper divisors (38774083519164).

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

21365564716356 is a wasteful number, since it uses less digits than its factorization.

21365564716356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37083022 (or 37082982 counting only the distinct ones).

The product of its digits is 81648000, while the sum is 60.

The spelling of 21365564716356 in words is "twenty-one trillion, three hundred sixty-five billion, five hundred sixty-four million, seven hundred sixteen thousand, three hundred fifty-six".