21115021201 has 2 divisors, whose sum is σ = 21115021202. Its totient is φ = 21115021200.

The previous prime is 21115021117. The next prime is 21115021259. The reversal of 21115021201 is 10212051112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10603850625 + 10511170576 = 102975^2 + 102524^2 .

It is a cyclic number.

It is not a de Polignac number, because 21115021201 - 2²⁹ = 20578150289 is a prime.

It is not a weakly prime, because it can be changed into another prime (21115024201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10557510600 + 10557510601.

It is an arithmetic number, because the mean of its divisors is an integer number (10557510601).

Almost surely, 2^21115021201 is an apocalyptic number.

It is an amenable number.

21115021201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21115021201 is an equidigital number, since it uses as much as digits as its factorization.

21115021201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40, while the sum is 16.

Adding to 21115021201 its reverse (10212051112), we get a palindrome (31327072313).

The spelling of 21115021201 in words is "twenty-one billion, one hundred fifteen million, twenty-one thousand, two hundred one".