The moon is shaped like a sphere.
Surface area of a sphere = 4 π r²
S.A = 4 * 3.14 * (1,080mi)²
S.A = 14,649,984 square miles
Volume of a sphere = 4/3 π r³
V = 4/3 * 3.14 * (1,080mi)³
V = 5,273,994,240
Surface area to volume ratio:
14,649,984 square miles ÷ 5,273,994,240 cubic miles = 0.00278/mile