21202112111121 has 8 divisors (see below), whose sum is σ = 31410536460960. Its totient is φ = 14134741407396.

The previous prime is 21202112111101. The next prime is 21202112111207. The reversal of 21202112111121 is 12111121120212.

It is a happy number.

21202112111121 is a `hidden beast` number, since 2 + 120 + 211 + 211 + 1 + 121 = 666.

It is not a de Polignac number, because 21202112111121 - 2¹⁰ = 21202112110097 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21202112111094 and 21202112111103.

It is not an unprimeable number, because it can be changed into a prime (21202112111101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 392631705735 + ... + 392631705788.

It is an arithmetic number, because the mean of its divisors is an integer number (3926317057620).

Almost surely, 2^{21202112111121} is an apocalyptic number.

It is an amenable number.

21202112111121 is a deficient number, since it is larger than the sum of its proper divisors (10208424349839).

21202112111121 is an equidigital number, since it uses as much as digits as its factorization.

21202112111121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 785263411532 (or 785263411526 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21202112111121 its reverse (12111121120212), we get a palindrome (33313233231333).

Subtracting from 21202112111121 its reverse (12111121120212), we obtain a palindrome (9090990990909).

The spelling of 21202112111121 in words is "twenty-one trillion, two hundred two billion, one hundred twelve million, one hundred eleven thousand, one hundred twenty-one".