719

Number
$719$ (seven hundred and nineteen) is:


 * The $128$th prime number.


 * The $32$nd Sophie Germain prime after $2$, $3$, $5$, $11$, $23$, $29$, $41$, $\ldots$, $233$, $239$, $251$, $281$, $293$, $359$, $419$, $431$, $443$, $491$, $509$, $593$, $641$, $653$, $659$, $683$:
 * $2 \times 719 + 1 = 1439$, which is prime.


 * The smaller of the $10$th pair of primes whose prime gap is $8$:
 * $727 - 719 = 8$


 * The $4$th term after $89$, $179$, $359$ of the smallest sequence of $6$ primes formed by doubling and adding one:
 * $\left({89, 179, 359, 719, 1439, 2879}\right)$