21616025116521 has 32 divisors (see below), whose sum is σ = 32509736534016. Its totient is φ = 12656925360000.

The previous prime is 21616025116501. The next prime is 21616025116547. The reversal of 21616025116521 is 12561152061612.

It is not a de Polignac number, because 21616025116521 - 2⁷ = 21616025116393 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21616025116521.

It is not an unprimeable number, because it can be changed into a prime (21616025116501) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16964241 + ... + 18193886.

It is an arithmetic number, because the mean of its divisors is an integer number (1015929266688).

Almost surely, 2^{21616025116521} is an apocalyptic number.

It is an amenable number.

21616025116521 is a deficient number, since it is larger than the sum of its proper divisors (10893711417495).

21616025116521 is a wasteful number, since it uses less digits than its factorization.

21616025116521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35158773.

The product of its (nonzero) digits is 43200, while the sum is 39.

The spelling of 21616025116521 in words is "twenty-one trillion, six hundred sixteen billion, twenty-five million, one hundred sixteen thousand, five hundred twenty-one".