Is it permissible to open a savings account in an Arab bank without interest, but benefiting from the monthly prize system granted by the bank based on account numbers?

If the bank deals in usury, then it is not permissible. These prizes are the very essence of usurious interest. The difference in the distribution method combines usury and gambling, because the customer will deposit his money in the hope of being one of the winners, and he may not be chosen.