206563664641 has 2 divisors, whose sum is σ = 206563664642. Its totient is φ = 206563664640.

The previous prime is 206563664569. The next prime is 206563664689. The reversal of 206563664641 is 146466365602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 150901171600 + 55662493041 = 388460^2 + 235929^2 .

It is a cyclic number.

It is not a de Polignac number, because 206563664641 - 2¹⁵ = 206563631873 is a prime.

It is not a weakly prime, because it can be changed into another prime (206563665641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103281832320 + 103281832321.

It is an arithmetic number, because the mean of its divisors is an integer number (103281832321).

Almost surely, 2^206563664641 is an apocalyptic number.

It is an amenable number.

206563664641 is a deficient number, since it is larger than the sum of its proper divisors (1).

206563664641 is an equidigital number, since it uses as much as digits as its factorization.

206563664641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3732480, while the sum is 49.

The spelling of 206563664641 in words is "two hundred six billion, five hundred sixty-three million, six hundred sixty-four thousand, six hundred forty-one".