How many barrels is the farmer going to need? math q?

a grain silo is in the shape of a cylinder with a hemisphere placed on top. the radius of the cylinder and the hemisphere is 24 feet and 6 inches. the height of the cylinder is 45 feet. the silo is 97% full with grain. the farmer is going to put all the grain in barrels that hold 20 gallons each. how many barrels is the farmer going to need?