21200110021 has 2 divisors, whose sum is σ = 21200110022. Its totient is φ = 21200110020.

The previous prime is 21200109977. The next prime is 21200110093. The reversal of 21200110021 is 12001100212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17242316100 + 3957793921 = 131310^2 + 62911^2 .

It is a cyclic number.

It is not a de Polignac number, because 21200110021 - 2⁷ = 21200109893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21200110121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600055010 + 10600055011.

It is an arithmetic number, because the mean of its divisors is an integer number (10600055011).

Almost surely, 2^21200110021 is an apocalyptic number.

It is an amenable number.

21200110021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200110021 is an equidigital number, since it uses as much as digits as its factorization.

21200110021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21200110021 its reverse (12001100212), we get a palindrome (33201210233).

It can be divided in two parts, 2 and 1200110021, that multiplied together give a palindrome (2400220042).

The spelling of 21200110021 in words is "twenty-one billion, two hundred million, one hundred ten thousand, twenty-one".