205666366253 has 2 divisors, whose sum is σ = 205666366254. Its totient is φ = 205666366252.

The previous prime is 205666366247. The next prime is 205666366271. The reversal of 205666366253 is 352663666502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 204559007524 + 1107358729 = 452282^2 + 33277^2 .

It is a cyclic number.

It is not a de Polignac number, because 205666366253 - 2⁴ = 205666366237 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205666366223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102833183126 + 102833183127.

It is an arithmetic number, because the mean of its divisors is an integer number (102833183127).

Almost surely, 2^205666366253 is an apocalyptic number.

It is an amenable number.

205666366253 is a deficient number, since it is larger than the sum of its proper divisors (1).

205666366253 is an equidigital number, since it uses as much as digits as its factorization.

205666366253 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6998400, while the sum is 50.

The spelling of 205666366253 in words is "two hundred five billion, six hundred sixty-six million, three hundred sixty-six thousand, two hundred fifty-three".