21211200112121 has 2 divisors, whose sum is σ = 21211200112122. Its totient is φ = 21211200112120.

The previous prime is 21211200112087. The next prime is 21211200112153. The reversal of 21211200112121 is 12121100211212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21115449474025 + 95750638096 = 4595155^2 + 309436^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211200112121 - 2⁴² = 16813153601017 is a prime.

It is a super-2 number, since 2×21211200112121² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21211200112121.

It is not a weakly prime, because it can be changed into another prime (21211200192121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605600056060 + 10605600056061.

It is an arithmetic number, because the mean of its divisors is an integer number (10605600056061).

Almost surely, 2^{21211200112121} is an apocalyptic number.

It is an amenable number.

21211200112121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211200112121 is an equidigital number, since it uses as much as digits as its factorization.

21211200112121 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 21211200112121 its reverse (12121100211212), we get a palindrome (33332300323333).

Subtracting from 21211200112121 its reverse (12121100211212), we obtain a palindrome (9090099900909).

The spelling of 21211200112121 in words is "twenty-one trillion, two hundred eleven billion, two hundred million, one hundred twelve thousand, one hundred twenty-one".