347

Number

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

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 $11$th Friedman number base $10$ after $25$, $121$, $125$, $126$, $127$, $128$, $153$, $216$, $289$, $343$:

$347 = 7^3 + 4$

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 $349$

The $26$th left-truncatable prime after $2$, $3$, $5$, $7$, $\ldots$, $197$, $223$, $283$, $313$, $317$, $337$