20979911802156 has 24 divisors (see below), whose sum is σ = 51529607935680. Its totient is φ = 6625235305872.

The previous prime is 20979911802151. The next prime is 20979911802163. The reversal of 20979911802156 is 65120811997902.

It is a self number, because there is not a number n which added to its sum of digits gives 20979911802156.

It is not an unprimeable number, because it can be changed into a prime (20979911802151) 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 7 ways as a sum of consecutive naturals, for example, 46008578286 + ... + 46008578741.

It is an arithmetic number, because the mean of its divisors is an integer number (2147066997320).

Almost surely, 2^{20979911802156} is an apocalyptic number.

It is an amenable number.

20979911802156 is an abundant number, since it is smaller than the sum of its proper divisors (30549696133524).

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

20979911802156 is a wasteful number, since it uses less digits than its factorization.

20979911802156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92017157053 (or 92017157051 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 60.

The spelling of 20979911802156 in words is "twenty trillion, nine hundred seventy-nine billion, nine hundred eleven million, eight hundred two thousand, one hundred fifty-six".