1) There is no uniform serial number, each chip manufacturer uses its own scheme. This is the reason, that projects using cards from several suppliers specify, how to retrieve it on a uniform way. Situation is better on Desfire, where there is only one supplier.
2) All cards I encountered, had no number printed on it. I doubt, that there is a reliable relation from a number printed on the card and its serial number, since this requires some effort during production and can be easily delegated to the customer. I would assume its more something like an order number.