21201121222111 has 2 divisors, whose sum is σ = 21201121222112. Its totient is φ = 21201121222110.

The previous prime is 21201121222093. The next prime is 21201121222181. The reversal of 21201121222111 is 11122212110212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21201121222111 - 2¹¹ = 21201121220063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201121222181) 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, 10600560611055 + 10600560611056.

It is an arithmetic number, because the mean of its divisors is an integer number (10600560611056).

Almost surely, 2^{21201121222111} is an apocalyptic number.

21201121222111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201121222111 is an equidigital number, since it uses as much as digits as its factorization.

21201121222111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21201121222111 its reverse (11122212110212), we get a palindrome (32323333332323).

The spelling of 21201121222111 in words is "twenty-one trillion, two hundred one billion, one hundred twenty-one million, two hundred twenty-two thousand, one hundred eleven".