Calculate the number 6669

Sister Mary Ann, who worked for a home health agency, was making her rounds. She was visiting homebound patients when she ran out of gas.
As luck would have it, a gas station was just a block away. She walked to the station to borrow a gas can and buy some gas. The attendant told her that the only gas can he owned had been loaned out, but she could wait until it was returned
Since Sister Mary Ann was on the way to see a patient, she decided not to wait and walked back to her car. She looked for something in her car that she could fill with gas and spotted the bedpan she was taking to the patient. Always resourceful, Sister Mary Ann carried the bedpan to the station, filled it with gasoline, and carried the full bedpan back to her car.
As she was pouring the gas into her tank, two Baptists watched from across the street. One of them turned to the other and said, "If it starts, I'm becoming Catholic."