21201021101121 has 16 divisors (see below), whose sum is σ = 29300363249664. Its totient is φ = 13626823337424.

The previous prime is 21201021101087. The next prime is 21201021101129. The reversal of 21201021101121 is 12110112010212.

It is a happy number.

It is not a de Polignac number, because 21201021101121 - 2⁴¹ = 19001997845569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21201021101121.

It is not an unprimeable number, because it can be changed into a prime (21201021101129) 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, 1122093925 + ... + 1122112818.

It is an arithmetic number, because the mean of its divisors is an integer number (1831272703104).

Almost surely, 2^{21201021101121} is an apocalyptic number.

It is an amenable number.

21201021101121 is a deficient number, since it is larger than the sum of its proper divisors (8099342148543).

21201021101121 is a wasteful number, since it uses less digits than its factorization.

21201021101121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2244206860.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21201021101121 its reverse (12110112010212), we get a palindrome (33311133111333).

Subtracting from 21201021101121 its reverse (12110112010212), we obtain a palindrome (9090909090909).

It can be divided in two parts, 2120102 and 1101121, that added together give a palindrome (3221223).

The spelling of 21201021101121 in words is "twenty-one trillion, two hundred one billion, twenty-one million, one hundred one thousand, one hundred twenty-one".