607

Number
$607$ (six hundred and seven) is:


 * The $111$th prime number


 * The $11$th balanced prime after $5$, $53$, $157$, $173$, $211$, $257$, $263$, $373$, $563$, $593$:
 * $607 = \dfrac {601 + 613} 2$


 * The index of the $14$th Mersenne prime after $2$, $3$, $5$, $7$, $13$, $17$, $19$, $31$, $61$, $89$, $107$, $127$, $521$:
 * $M_{607} = 2^{607} - 1 \approx 5 \cdotp 311 \times 10^{182}$


 * The $18$th of $29$ primes of the form $2 x^2 + 29$:
 * $2 \times 17^2 + 29 = 607$