212100122111021 has 2 divisors, whose sum is σ = 212100122111022. Its totient is φ = 212100122111020.

The previous prime is 212100122110979. The next prime is 212100122111051. The reversal of 212100122111021 is 120111221001212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 182227185714025 + 29872936396996 = 13499155^2 + 5465614^2 .

It is a cyclic number.

It is not a de Polignac number, because 212100122111021 - 2⁶ = 212100122110957 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212100122111051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106050061055510 + 106050061055511.

It is an arithmetic number, because the mean of its divisors is an integer number (106050061055511).

Almost surely, 2^{212100122111021} is an apocalyptic number.

It is an amenable number.

212100122111021 is a deficient number, since it is larger than the sum of its proper divisors (1).

212100122111021 is an equidigital number, since it uses as much as digits as its factorization.

212100122111021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 212100122111021 its reverse (120111221001212), we get a palindrome (332211343112233).

The spelling of 212100122111021 in words is "two hundred twelve trillion, one hundred billion, one hundred twenty-two million, one hundred eleven thousand, twenty-one".