347

Number
$347$ (three hundred and forty-seven) is:


 * The $69$th prime number


 * The larger of the $5$th pair of primes whose prime gap is $10$:
 * $347 - 337 = 10$


 * The upper end of the $6$th record-breaking gap between twin primes:
 * $347 - 313 = 34$


 * The $13$th safe prime after $5$, $7$, $11$, $23$, $47$, $59$, $83$, $107$, $167$, $179$, $227$, $263$:
 * $347 = 2 \times 173 + 1$


 * The $18$th emirp after $13$, $17$, $31$, $37$, $71$, $73$, $79$, $97$, $107$, $113$, $149$, $157$, $167$, $179$, $199$, $311$, $337$


 * The smaller of the $21$st pair of twin primes, with $349$