21115344403207 has 2 divisors, whose sum is σ = 21115344403208. Its totient is φ = 21115344403206.

The previous prime is 21115344403117. The next prime is 21115344403243. The reversal of 21115344403207 is 70230444351112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21115344403207 - 2²³ = 21115336014599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21115344403267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10557672201603 + 10557672201604.

It is an arithmetic number, because the mean of its divisors is an integer number (10557672201604).

Almost surely, 2^{21115344403207} is an apocalyptic number.

21115344403207 is a deficient number, since it is larger than the sum of its proper divisors (1).

21115344403207 is an equidigital number, since it uses as much as digits as its factorization.

21115344403207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80640, while the sum is 37.

Adding to 21115344403207 its reverse (70230444351112), we get a palindrome (91345788754319).

The spelling of 21115344403207 in words is "twenty-one trillion, one hundred fifteen billion, three hundred forty-four million, four hundred three thousand, two hundred seven".