21202110010021 has 2 divisors, whose sum is σ = 21202110010022. Its totient is φ = 21202110010020.

The previous prime is 21202110010009. The next prime is 21202110010051. The reversal of 21202110010021 is 12001001120212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20542377816900 + 659732193121 = 4532370^2 + 812239^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202110010021 - 2⁵ = 21202110009989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21202110009983 and 21202110010010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21202110010051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601055005010 + 10601055005011.

It is an arithmetic number, because the mean of its divisors is an integer number (10601055005011).

Almost surely, 2^{21202110010021} is an apocalyptic number.

It is an amenable number.

21202110010021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202110010021 is an equidigital number, since it uses as much as digits as its factorization.

21202110010021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21202110010021 its reverse (12001001120212), we get a palindrome (33203111130233).

The spelling of 21202110010021 in words is "twenty-one trillion, two hundred two billion, one hundred ten million, ten thousand, twenty-one".