Why are banks called debtors as well as creditors?
Debtor is a person who owes some amount of money and creditor is a person to whom money is owed.
A bank owes money to its depositors - that is why it is called debtor. On the other hand, a bank grants loans and all those who have taken loan owe money to banks. That is why a bank is also called creditor. A bank is a debtor for its depositors and creditor for its loan holders.