205109317 has 4 divisors (see below), whose sum is σ = 234410656. Its totient is φ = 175807980.

The previous prime is 205109297. The next prime is 205109323. The reversal of 205109317 is 713901502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 205109317 - 2¹¹ = 205107269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205109357) 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 in 3 ways as a sum of consecutive naturals, for example, 14650659 + ... + 14650672.

It is an arithmetic number, because the mean of its divisors is an integer number (58602664).

Almost surely, 2^205109317 is an apocalyptic number.

It is an amenable number.

205109317 is a deficient number, since it is larger than the sum of its proper divisors (29301339).

205109317 is an equidigital number, since it uses as much as digits as its factorization.

205109317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29301338.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 205109317 is about 14321.6380697181. The cubic root of 205109317 is about 589.7416440426.

The spelling of 205109317 in words is "two hundred five million, one hundred nine thousand, three hundred seventeen".