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WHAT ARE THE IMPORTANCE OF RAMANUJAN'S NUMBER?
It is the smallest number expressible as the sum of two cubes in two different ways.
The two different ways are these:

    1729 = 13 + 123 = 93 + 103
1729 is one of four positive integers (with the others being 81, 1458, and the trivial case 1) which, when its digits are added together, produces a sum which, when multiplied by its reversal, yields the original number:

    1 + 7 + 2 + 9 = 19
    19 × 91 = 1729


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