21112021111121 has 2 divisors, whose sum is σ = 21112021111122. Its totient is φ = 21112021111120.

The previous prime is 21112021111087. The next prime is 21112021111163. The reversal of 21112021111121 is 12111112021112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20470548264721 + 641472846400 = 4524439^2 + 800920^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112021111121 - 2²² = 21112016916817 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21112021111121.

It is not a weakly prime, because it can be changed into another prime (21112021111021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556010555560 + 10556010555561.

It is an arithmetic number, because the mean of its divisors is an integer number (10556010555561).

Almost surely, 2^{21112021111121} is an apocalyptic number.

It is an amenable number.

21112021111121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112021111121 is an equidigital number, since it uses as much as digits as its factorization.

21112021111121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 21112021111121 its reverse (12111112021112), we get a palindrome (33223133132233).

Subtracting from 21112021111121 its reverse (12111112021112), we obtain a palindrome (9000909090009).

The spelling of 21112021111121 in words is "twenty-one trillion, one hundred twelve billion, twenty-one million, one hundred eleven thousand, one hundred twenty-one".