21112222211 has 2 divisors, whose sum is σ = 21112222212. Its totient is φ = 21112222210.

The previous prime is 21112222181. The next prime is 21112222213. The reversal of 21112222211 is 11222221112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21112222211 - 2⁶ = 21112222147 is a prime.

Together with 21112222213, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21112222211.

It is not a weakly prime, because it can be changed into another prime (21112222213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556111105 + 10556111106.

It is an arithmetic number, because the mean of its divisors is an integer number (10556111106).

Almost surely, 2^21112222211 is an apocalyptic number.

21112222211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112222211 is an equidigital number, since it uses as much as digits as its factorization.

21112222211 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64, while the sum is 17.

Adding to 21112222211 its reverse (11222221112), we get a palindrome (32334443323).

The spelling of 21112222211 in words is "twenty-one billion, one hundred twelve million, two hundred twenty-two thousand, two hundred eleven".