21210322205021 has 2 divisors, whose sum is σ = 21210322205022. Its totient is φ = 21210322205020.

The previous prime is 21210322204987. The next prime is 21210322205087. The reversal of 21210322205021 is 12050222301212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17528582491225 + 3681739713796 = 4186715^2 + 1918786^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210322205021 - 2⁶ = 21210322204957 is a prime.

It is a super-2 number, since 2×21210322205021² (a number of 27 digits) contains 22 as substring.

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 (21210322205221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605161102510 + 10605161102511.

It is an arithmetic number, because the mean of its divisors is an integer number (10605161102511).

Almost surely, 2^{21210322205021} is an apocalyptic number.

It is an amenable number.

21210322205021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210322205021 is an equidigital number, since it uses as much as digits as its factorization.

21210322205021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 21210322205021 its reverse (12050222301212), we get a palindrome (33260544506233).

The spelling of 21210322205021 in words is "twenty-one trillion, two hundred ten billion, three hundred twenty-two million, two hundred five thousand, twenty-one".