2,147,483,647

Number
$2 \, 147 \, 483 \, 647$ is:


 * A prime number


 * The $8$th Mersenne prime after $3$, $7$, $31$, $127$, $8191$, $131 \, 071$, $524 \, 287$:
 * $2 \, 147 \, 483 \, 647 = 2^{31} - 1$