317

Number
$317$ (three hundred and seventeen) is:


 * The $66$th prime number


 * The $7$th of the sequence of $n$ such that $p_n \# - 1$, where $p_n \#$ denotes primorial of $n$, is prime:
 * $3, 5, 11, 13, 41, 89, 317$


 * The $13$th of $29$ primes of the form $2 x^2 + 29$:
 * $2 \times 12^2 + 29 = 317$