Saurabh and the Treasure

Problem statement : While Saurabh was travelling throughout the world, he found a large treasure chest. There was a number n written on the top of the chest where n is of the form x!/y! (x ≥ y).The treasure is guarded by Red Skull. He says that, you have to perform maximum number of operations where each operation is defined as "Choose a number m (m>1) which divides n and then replace n by n/m ".