21202010212921 has 2 divisors, whose sum is σ = 21202010212922. Its totient is φ = 21202010212920.

The previous prime is 21202010212907. The next prime is 21202010212949. The reversal of 21202010212921 is 12921201020212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21198758932521 + 3251280400 = 4604211^2 + 57020^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202010212921 - 2²³ = 21202001824313 is a prime.

It is not a weakly prime, because it can be changed into another prime (21202010213921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601005106460 + 10601005106461.

It is an arithmetic number, because the mean of its divisors is an integer number (10601005106461).

Almost surely, 2^{21202010212921} is an apocalyptic number.

It is an amenable number.

21202010212921 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202010212921 is an equidigital number, since it uses as much as digits as its factorization.

21202010212921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 25.

The spelling of 21202010212921 in words is "twenty-one trillion, two hundred two billion, ten million, two hundred twelve thousand, nine hundred twenty-one".