The credit card number you entered (378734493671000) is a valid credit card number according to the Luhn check!
The last 8 digits of your credit card are your personal account number. In your case, these are: 49367100.
The first digit of your credit card identifies the major industry it belongs to. Yours is a 3, so your card belongs to Travel and entertainment.
The first six digits of your credit card tell us which company (Visa, Mastercard, etc) has actually issued you your card. As far as we can tell, your card is a Amex credit card. Of course, there are a million possibilities here.
Wait--there is still more. Using our BIN Lookup Tool you might be able to decode the BIN bank code. You can try searching in our BIN Database