21222212111 has 2 divisors, whose sum is σ = 21222212112. Its totient is φ = 21222212110.

The previous prime is 21222212087. The next prime is 21222212129. The reversal of 21222212111 is 11121222212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21222212111 - 2⁶ = 21222212047 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21222212111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21222212161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611106055 + 10611106056.

It is an arithmetic number, because the mean of its divisors is an integer number (10611106056).

Almost surely, 2^21222212111 is an apocalyptic number.

21222212111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222212111 is an equidigital number, since it uses as much as digits as its factorization.

21222212111 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 21222212111 its reverse (11121222212), we get a palindrome (32343434323).

It can be divided in two parts, 21222212 and 111, that multiplied together give a palindrome (2355665532).

The spelling of 21222212111 in words is "twenty-one billion, two hundred twenty-two million, two hundred twelve thousand, one hundred eleven".