National Mathematics Day 2020: Why is 1729 a special number?

New Delhi, Dec 22: National Mathematics Day is celebrated each year in India on December 22, 2020 to mark the birth anniversary of legendary Indian mathematician - Srinivasa Ramanujan.

Born in Erode in 1887, S. Ramanujan went on to become a world renowned mathematician. His life was an awe inspiring journey that not only unravelled many mathematical principals but placed him squarely among the greatest minds of all times.

Why is 1729 a special number?

Ramanujan had interest in mathematics since childhood. 1729 is the natural number following 1728 and preceding 1730. It is a taxicab number, and is variously known as Ramanujan's number and the Ramanujan-Hardy number, after an anecdote of the British mathematician G. H. Hardy when he visited Indian mathematician Srinivasa Ramanujan in hospital.

1729, the Hardy-Ramanujan Number, is the smallest number which can be expressed as the sum of two different cubes in two different ways. 1729 is the sum of the cubes of 10 and 9 - cube of 10 is 1000 and cube of 9 is 729; adding the two numbers results in 1729.