20938449818881 has 8 divisors (see below), whose sum is σ = 23938562672640. Its totient is φ = 17940563399328.

The previous prime is 20938449818857. The next prime is 20938449818893. The reversal of 20938449818881 is 18881894483902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20938449818881 - 2²¹ = 20938447721729 is a prime.

It is a super-2 number, since 2×20938449818881² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20938449818081) 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, 556588396 + ... + 556626013.

It is an arithmetic number, because the mean of its divisors is an integer number (2992320334080).

Almost surely, 2^{20938449818881} is an apocalyptic number.

It is an amenable number.

20938449818881 is a deficient number, since it is larger than the sum of its proper divisors (3000112853759).

20938449818881 is a wasteful number, since it uses less digits than its factorization.

20938449818881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1113217103.

The product of its (nonzero) digits is 254803968, while the sum is 73.

The spelling of 20938449818881 in words is "twenty trillion, nine hundred thirty-eight billion, four hundred forty-nine million, eight hundred eighteen thousand, eight hundred eighty-one".