21102120111121 has 4 divisors (see below), whose sum is σ = 24116708698432. Its totient is φ = 18087531523812.

The previous prime is 21102120111113. The next prime is 21102120111173. The reversal of 21102120111121 is 12111102120112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21102120111121 - 2³ = 21102120111113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21102120111095 and 21102120111104.

It is not an unprimeable number, because it can be changed into a prime (21102120111521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1507294293645 + ... + 1507294293658.

It is an arithmetic number, because the mean of its divisors is an integer number (6029177174608).

Almost surely, 2^{21102120111121} is an apocalyptic number.

It is an amenable number.

21102120111121 is a deficient number, since it is larger than the sum of its proper divisors (3014588587311).

21102120111121 is an equidigital number, since it uses as much as digits as its factorization.

21102120111121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3014588587310.

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

Adding to 21102120111121 its reverse (12111102120112), we get a palindrome (33213222231233).

The spelling of 21102120111121 in words is "twenty-one trillion, one hundred two billion, one hundred twenty million, one hundred eleven thousand, one hundred twenty-one".