# Two Sums of Two Squares

**Number Theory**Level 4

The number 1729 is also known as Hardy-Ramanujan number, or the least natural number that can be expressed as the sum of two cubes in two different ways:

\[1729 = 1^3 + 12^3 = 9^3 + 10^3\]

Then what is the least natural number that can be expressed as the sum of two squares of different natural numbers in two different ways?