1523

Number
$1523$ (one thousand, five hundred and twenty-three) is:


 * The $241$st prime number.


 * The $34$th safe prime after $5$, $7$, $11$, $23$, $47$, $\ldots$, $839$, $863$, $887$, $983$, $1019$, $1187$, $1283$, $1307$, $1319$, $1367$, $1439$, $1487$:
 * $1523 = 2 \times 761 + 1$


 * The $59$th left-truncatable prime after $2$, $3$, $5$, $7$, $\ldots$, $743$, $773$, $797$, $823$, $853$, $883$, $937$, $947$, $953$, $967$, $983$, $997$, $1223$, $1283$, $1367$, $1373$