311

Number
$311$ (three hundred and eleven) is:


 * The $64$th prime number


 * The $16$th emirp after $13$, $17$, $31$, $37$, $71$, $73$, $79$, $97$, $107$, $113$, $149$, $157$, $167$, $179$, $199$


 * The $17$th permutable prime after $2, 3, 5, 7, 11, 13, 17, 31, 37, 71, 73, 79, 97, 113, 131, 199$


 * The $1$st of the $20$th pair of twin primes, with $313$

Also see