1729 is the Ramanujan’s number. When the great Indian mathematician was lying ill in the hospital, Dr. Hardy came to visit him. He said ,the taxi number 1729, in which he came is a boring number.Suddenly Ramanujan’s face lit up & he said , it is not a boring number. It is the only number that is the sum of 2 cubes in two different ways.
10^3 + 9^3 = 1729 & 12^3 + 1^3 = 1729.