205317672517 has 2 divisors, whose sum is σ = 205317672518. Its totient is φ = 205317672516.

The previous prime is 205317672503. The next prime is 205317672541. The reversal of 205317672517 is 715276713502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168472486116 + 36845186401 = 410454^2 + 191951^2 .

It is a cyclic number.

It is not a de Polignac number, because 205317672517 - 2³⁵ = 170957934149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205317672577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102658836258 + 102658836259.

It is an arithmetic number, because the mean of its divisors is an integer number (102658836259).

Almost surely, 2^205317672517 is an apocalyptic number.

It is an amenable number.

205317672517 is a deficient number, since it is larger than the sum of its proper divisors (1).

205317672517 is an equidigital number, since it uses as much as digits as its factorization.

205317672517 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 617400, while the sum is 46.

The spelling of 205317672517 in words is "two hundred five billion, three hundred seventeen million, six hundred seventy-two thousand, five hundred seventeen".