21112202210261 has 2 divisors, whose sum is σ = 21112202210262. Its totient is φ = 21112202210260.

The previous prime is 21112202210257. The next prime is 21112202210299. The reversal of 21112202210261 is 16201220221112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20449433631025 + 662768579236 = 4522105^2 + 814106^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112202210261 - 2² = 21112202210257 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112202210161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556101105130 + 10556101105131.

It is an arithmetic number, because the mean of its divisors is an integer number (10556101105131).

Almost surely, 2^{21112202210261} is an apocalyptic number.

It is an amenable number.

21112202210261 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112202210261 is an equidigital number, since it uses as much as digits as its factorization.

21112202210261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 23.

Adding to 21112202210261 its reverse (16201220221112), we get a palindrome (37313422431373).

The spelling of 21112202210261 in words is "twenty-one trillion, one hundred twelve billion, two hundred two million, two hundred ten thousand, two hundred sixty-one".