83

Number
$83$ (eighty-three) is:


 * The $23$rd prime number


 * The $9$th Sophie Germain prime after $2$, $3$, $5$, $11$, $23$, $29$, $41$, $53$:
 * $2 \times 83 + 1 = 167$, which is prime.


 * The $7$th of $11$ primes of the form $2 x^2 + 11$:
 * $2 \times 6^2 + 11 = 83$