21011221022111 has 2 divisors, whose sum is σ = 21011221022112. Its totient is φ = 21011221022110.

The previous prime is 21011221022093. The next prime is 21011221022149. The reversal of 21011221022111 is 11122012211012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21011221022111 - 2⁶ = 21011221022047 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21011221022111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011221022611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505610511055 + 10505610511056.

It is an arithmetic number, because the mean of its divisors is an integer number (10505610511056).

Almost surely, 2^{21011221022111} is an apocalyptic number.

21011221022111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011221022111 is an equidigital number, since it uses as much as digits as its factorization.

21011221022111 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21011221022111 its reverse (11122012211012), we get a palindrome (32133233233123).

The spelling of 21011221022111 in words is "twenty-one trillion, eleven billion, two hundred twenty-one million, twenty-two thousand, one hundred eleven".