21211102120111 has 4 divisors (see below), whose sum is σ = 21527685733912. Its totient is φ = 20894518506312.

The previous prime is 21211102120097. The next prime is 21211102120133. The reversal of 21211102120111 is 11102120111212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21211102120111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211102120211) 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, 158291806800 + ... + 158291806933.

It is an arithmetic number, because the mean of its divisors is an integer number (5381921433478).

Almost surely, 2^{21211102120111} is an apocalyptic number.

21211102120111 is a deficient number, since it is larger than the sum of its proper divisors (316583613801).

21211102120111 is an equidigital number, since it uses as much as digits as its factorization.

21211102120111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316583613800.

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

Adding to 21211102120111 its reverse (11102120111212), we get a palindrome (32313222231323).

It can be divided in two parts, 212 and 11102120111, that multiplied together give a palindrome (2353649463532).

The spelling of 21211102120111 in words is "twenty-one trillion, two hundred eleven billion, one hundred two million, one hundred twenty thousand, one hundred eleven".