21201221120111 has 2 divisors, whose sum is σ = 21201221120112. Its totient is φ = 21201221120110.

The previous prime is 21201221120081. The next prime is 21201221120197. The reversal of 21201221120111 is 11102112210212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21201221120111 - 2⁶ = 21201221120047 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21201221120111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201221123111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600610560055 + 10600610560056.

It is an arithmetic number, because the mean of its divisors is an integer number (10600610560056).

Almost surely, 2^{21201221120111} is an apocalyptic number.

21201221120111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201221120111 is an equidigital number, since it uses as much as digits as its factorization.

21201221120111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21201221120111 its reverse (11102112210212), we get a palindrome (32303333330323).

The spelling of 21201221120111 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-one million, one hundred twenty thousand, one hundred eleven".