21102112111 has 4 divisors (see below), whose sum is σ = 21102525424. Its totient is φ = 21101698800.

The previous prime is 21102112093. The next prime is 21102112133. The reversal of 21102112111 is 11121120112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21102112111 - 2⁵ = 21102112079 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21102112091 and 21102112100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102113111) 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, 117150 + ... + 236491.

It is an arithmetic number, because the mean of its divisors is an integer number (5275631356).

Almost surely, 2^21102112111 is an apocalyptic number.

21102112111 is a deficient number, since it is larger than the sum of its proper divisors (413313).

21102112111 is an equidigital number, since it uses as much as digits as its factorization.

21102112111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413312.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21102112111 its reverse (11121120112), we get a palindrome (32223232223).

The spelling of 21102112111 in words is "twenty-one billion, one hundred two million, one hundred twelve thousand, one hundred eleven".