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 $313$.