211261345817 has 2 divisors, whose sum is σ = 211261345818. Its totient is φ = 211261345816.

The previous prime is 211261345787. The next prime is 211261345853. The reversal of 211261345817 is 718543162112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 206137792576 + 5123553241 = 454024^2 + 71579^2 .

It is a cyclic number.

It is not a de Polignac number, because 211261345817 - 2⁶ = 211261345753 is a prime.

It is not a weakly prime, because it can be changed into another prime (211261344817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105630672908 + 105630672909.

It is an arithmetic number, because the mean of its divisors is an integer number (105630672909).

Almost surely, 2^211261345817 is an apocalyptic number.

It is an amenable number.

211261345817 is a deficient number, since it is larger than the sum of its proper divisors (1).

211261345817 is an equidigital number, since it uses as much as digits as its factorization.

211261345817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 41.

The spelling of 211261345817 in words is "two hundred eleven billion, two hundred sixty-one million, three hundred forty-five thousand, eight hundred seventeen".