Yup - it's generated by your bank (and thus tied to it in their databases) so they are the only ones who knows what credit card number it's tied to. It's a random number so there is no way to decrypt it to figure out your original credit card number.

It's useless by itself unless it has the authenticated token along with it - which only the specific device the device number is tied to can generate. When you make a payment from your phone your device sends the device number and the one time use token to the merchant, who then forwards it on to the processor, who in turn forward it to the issuing bank to verify.

If you're using apple pay - the only way to get your credit card number is to either physically pry it out of your wallet or hack the bank.