Finding primes

Let $P(N)$ be the probability that a randomly chosen integer, $N$ , is prime. If $P(N) = x/(6\ln N)$ Then find the value of $x$ where $x$ is an integer.

Note: Assume that $N$ is very large, and ignore terms in your answer that are of subleading order in $N$ . Also, make the assumption that the probability that $N$ is divisible by a prime $p$ is exactly $1/p$ (which is essentially true, for a large enough sample size of numbers).