21221100020121 has 32 divisors (see below), whose sum is σ = 29833006579200. Its totient is φ = 13380750673920.

The previous prime is 21221100020051. The next prime is 21221100020137. The reversal of 21221100020121 is 12102000112212.

It is not a de Polignac number, because 21221100020121 - 2²⁶ = 21221032911257 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21221100020121.

It is not an unprimeable number, because it can be changed into a prime (21221100020161) 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, 699266470 + ... + 699296816.

It is an arithmetic number, because the mean of its divisors is an integer number (932281455600).

Almost surely, 2^{21221100020121} is an apocalyptic number.

It is an amenable number.

21221100020121 is a deficient number, since it is larger than the sum of its proper divisors (8611906559079).

21221100020121 is a wasteful number, since it uses less digits than its factorization.

21221100020121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50149.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21221100020121 its reverse (12102000112212), we get a palindrome (33323100132333).

The spelling of 21221100020121 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred million, twenty thousand, one hundred twenty-one".