666,649

Number
$666 \, 649$ (six hundred and sixty-six thousand, six hundred and forty-nine) is:


 * The $54 \, 999$th prime number


 * The $22$nd minimal prime base $10$ after $2$, $3$, $5$, $7$, $11$, $19$, $41$, $61$, $89$, $409$, $449$, $499$, $881$, $991$, $6469$, $6949$, $9001$, $9049$, $9649$, $9949$, $60 \, 649$