20938449818879 has 16 divisors (see below), whose sum is σ = 21552332256000. Its totient is φ = 20333624604480.

The previous prime is 20938449818857. The next prime is 20938449818893. The reversal of 20938449818879 is 97881894483902.

It is a cyclic number.

It is not a de Polignac number, because 20938449818879 - 2²⁸ = 20938181383423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20938449815879) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3901382 + ... + 7556300.

It is an arithmetic number, because the mean of its divisors is an integer number (1347020766000).

Almost surely, 2^{20938449818879} is an apocalyptic number.

20938449818879 is a deficient number, since it is larger than the sum of its proper divisors (613882437121).

20938449818879 is a wasteful number, since it uses less digits than its factorization.

20938449818879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3656158.

The product of its (nonzero) digits is 2006581248, while the sum is 80.

The spelling of 20938449818879 in words is "twenty trillion, nine hundred thirty-eight billion, four hundred forty-nine million, eight hundred eighteen thousand, eight hundred seventy-nine".