20556812016168 has 64 divisors (see below), whose sum is σ = 52701433315200. Its totient is φ = 6679852354560.

The previous prime is 20556812016163. The next prime is 20556812016269. The reversal of 20556812016168 is 86161021865502.

It is a self number, because there is not a number n which added to its sum of digits gives 20556812016168.

It is not an unprimeable number, because it can be changed into a prime (20556812016163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67622821 + ... + 67926132.

It is an arithmetic number, because the mean of its divisors is an integer number (823459895550).

Almost surely, 2^{20556812016168} is an apocalyptic number.

It is an amenable number.

20556812016168 is an abundant number, since it is smaller than the sum of its proper divisors (32144621299032).

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

20556812016168 is a wasteful number, since it uses less digits than its factorization.

20556812016168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135549122 (or 135549118 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 51.

The spelling of 20556812016168 in words is "twenty trillion, five hundred fifty-six billion, eight hundred twelve million, sixteen thousand, one hundred sixty-eight".