21112101202121 has 2 divisors, whose sum is σ = 21112101202122. Its totient is φ = 21112101202120.

The previous prime is 21112101202009. The next prime is 21112101202169. The reversal of 21112101202121 is 12120210121112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10982171812096 + 10129929390025 = 3313936^2 + 3182755^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112101202121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21112101202121.

It is not a weakly prime, because it can be changed into another prime (21112101202321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556050601060 + 10556050601061.

It is an arithmetic number, because the mean of its divisors is an integer number (10556050601061).

Almost surely, 2^{21112101202121} is an apocalyptic number.

It is an amenable number.

21112101202121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112101202121 is an equidigital number, since it uses as much as digits as its factorization.

21112101202121 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 21112101202121 its reverse (12120210121112), we get a palindrome (33232311323233).

The spelling of 21112101202121 in words is "twenty-one trillion, one hundred twelve billion, one hundred one million, two hundred two thousand, one hundred twenty-one".