206563664369 has 2 divisors, whose sum is σ = 206563664370. Its totient is φ = 206563664368.

The previous prime is 206563664299. The next prime is 206563664381. The reversal of 206563664369 is 963466365602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129841312225 + 76722352144 = 360335^2 + 276988^2 .

It is a cyclic number.

It is not a de Polignac number, because 206563664369 - 2³² = 202268697073 is a prime.

It is a super-2 number, since 2×206563664369² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (206563664399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103281832184 + 103281832185.

It is an arithmetic number, because the mean of its divisors is an integer number (103281832185).

Almost surely, 2^206563664369 is an apocalyptic number.

It is an amenable number.

206563664369 is a deficient number, since it is larger than the sum of its proper divisors (1).

206563664369 is an equidigital number, since it uses as much as digits as its factorization.

206563664369 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25194240, while the sum is 56.

The spelling of 206563664369 in words is "two hundred six billion, five hundred sixty-three million, six hundred sixty-four thousand, three hundred sixty-nine".