719

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


 * The $128$th prime number.


 * 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:
 * $\left({89, 179, 359, 719, 1439, 2879}\right)$