Assume that protons and neutrons have equal masses. Mass of a nucleon is \( 1.6 \times 10^{-27} \, \text{kg} \) and radius of nucleus is \( 1.5 \times 10^{-15} A^{1/3} \, \text{m} \). The approximate ratio of the nuclear density and water density is \( n \times 10^{13} \). The value of \( n \) is ________.
