21112211110121 has 2 divisors, whose sum is σ = 21112211110122. Its totient is φ = 21112211110120.

The previous prime is 21112211110091. The next prime is 21112211110127. The reversal of 21112211110121 is 12101111221112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21073975609600 + 38235500521 = 4590640^2 + 195539^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112211110121 - 2⁴² = 16714164599017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21112211110121.

It is not a weakly prime, because it can be changed into another prime (21112211110127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556105555060 + 10556105555061.

It is an arithmetic number, because the mean of its divisors is an integer number (10556105555061).

Almost surely, 2^{21112211110121} is an apocalyptic number.

It is an amenable number.

21112211110121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112211110121 is an equidigital number, since it uses as much as digits as its factorization.

21112211110121 is an evil number, because the sum of its binary digits is even.

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

Adding to 21112211110121 its reverse (12101111221112), we get a palindrome (33213322331233).

The spelling of 21112211110121 in words is "twenty-one trillion, one hundred twelve billion, two hundred eleven million, one hundred ten thousand, one hundred twenty-one".