21201110111 has 2 divisors, whose sum is σ = 21201110112. Its totient is φ = 21201110110.

The previous prime is 21201110083. The next prime is 21201110113. The reversal of 21201110111 is 11101110212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21201110111 - 2²² = 21196915807 is a prime.

Together with 21201110113, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21201110092 and 21201110101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201110113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600555055 + 10600555056.

It is an arithmetic number, because the mean of its divisors is an integer number (10600555056).

Almost surely, 2^21201110111 is an apocalyptic number.

21201110111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201110111 is an equidigital number, since it uses as much as digits as its factorization.

21201110111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21201110111 its reverse (11101110212), we get a palindrome (32302220323).

The spelling of 21201110111 in words is "twenty-one billion, two hundred one million, one hundred ten thousand, one hundred eleven".