205385690717 has 2 divisors, whose sum is σ = 205385690718. Its totient is φ = 205385690716.

The previous prime is 205385690693. The next prime is 205385690747. The reversal of 205385690717 is 717096583502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 191335381561 + 14050309156 = 437419^2 + 118534^2 .

It is a cyclic number.

It is not a de Polignac number, because 205385690717 - 2¹⁰ = 205385689693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205385690747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102692845358 + 102692845359.

It is an arithmetic number, because the mean of its divisors is an integer number (102692845359).

Almost surely, 2^205385690717 is an apocalyptic number.

It is an amenable number.

205385690717 is a deficient number, since it is larger than the sum of its proper divisors (1).

205385690717 is an equidigital number, since it uses as much as digits as its factorization.

205385690717 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3175200, while the sum is 53.

The spelling of 205385690717 in words is "two hundred five billion, three hundred eighty-five million, six hundred ninety thousand, seven hundred seventeen".