Starting Idea Of Ramanujan Number

 In 1918, Indian mathematician Srinivas Ramanujan was admitted to the hospital in London, where he was visited by his colleague and long-time friend G H Hardy. The fellow mathematician had arrived in a taxi which was numbered '1729' and had thought about it on his way to the room, upon entering Ramanujan's room, Hardy blurted "it was rather a dull number," after a brief hello.

When Ramanujan came to know of the number, the mathematician said "No Hardy, it is a very interesting number. It is the smallest number expressible as the sum of two cubes in two different ways."