Can you solve it? The London cab that rode into history

Do you have the knowledge?

UPDATE: Answers are now up.

Around 1919, the British mathematician G. H. Hardy hopped on a London cab on his way to visit his Indian colleague Srinivasa Ramanujan.

The cab's licence number, 1729, seemed dull to Hardy but his pal fervently disagreed. It is a very interesting number," said Ramanujan. It is the smallest number expressible as the sum of two cubes in two different ways."