How many natural numbers are there with the property that they can be expressed as sum of cubes of two natural numbers in two different ways.

Answer 1

probably infinitely many, but the smallest is

1729 = 1^3 + 12^3 = 9^3 + 10^3

as G.H. Hardy learned from Ramanujan.

Answer 2

steve now give me two different ways for it for my last question