1511

Number
$1511$ (one thousand, five hundred and eleven) is:


 * The $240$th prime number.


 * The $51$st Sophie Germain prime after $2$, $3$, $5$, $11$, $23$, $29$, $41$, $\ldots$, $1031$, $1049$, $1103$, $1223$, $1229$, $1289$, $1409$, $1439$, $1451$, $1481$, $1499$:
 * $2 \times 1511 + 1 = 3023$, which is prime.