The number '1729' is considered as an interesting number as it is the smallest natural number that can be written as the sum of cubes in two ways - sum of the cubes of 12 and 1 and the sum of the cubes of 10 and 9. What is this number '1729' popularly known as?

A

Landau-Ramanujan Constant

B

Hardy-Ramanujan Number

C

Ramanujan-Soldner Number

D

None of the above