Ramanujan and Taxi 1729

Ramanujan, a handsome fellow, was employed in the depths of Indian railways as a clerk. But he took the view that he was a sound mathematician and wrote unbidden to GH Hardy a mathematics don of Trinity College Cambridge. Hardy did not immediately respond but finally realised just how clever Ramanujan was and therefore invited him to Cambridge where his genius came to be recognised.

Some years later Hardy visited Ramanujan in hospital and remarked that his taxi number was 1729 and added that this was not an interesting number. To which Ramanujan immediately replied that, far from it, 1729 was most interesting since it was the lowest number which equalled two distinct pairs of cubed numbers. 1729 is 10 cubed and 9 cubed and, also, 12 cubed and 1 cubed.

Ramanujan died aged 33. in 1920.