201221002121021 has 2 divisors, whose sum is σ = 201221002121022. Its totient is φ = 201221002121020.

The previous prime is 201221002121011. The next prime is 201221002121039. The reversal of 201221002121021 is 120121200122102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 195133240380100 + 6087761740921 = 13969010^2 + 2467339^2 .

It is a cyclic number.

It is not a de Polignac number, because 201221002121021 - 2²⁶ = 201220935012157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201221002121011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100610501060510 + 100610501060511.

It is an arithmetic number, because the mean of its divisors is an integer number (100610501060511).

Almost surely, 2^{201221002121021} is an apocalyptic number.

It is an amenable number.

201221002121021 is a deficient number, since it is larger than the sum of its proper divisors (1).

201221002121021 is an equidigital number, since it uses as much as digits as its factorization.

201221002121021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 201221002121021 its reverse (120121200122102), we get a palindrome (321342202243123).

The spelling of 201221002121021 in words is "two hundred one trillion, two hundred twenty-one billion, two million, one hundred twenty-one thousand, twenty-one".