Ask a Teacher

Search



what is Ramanujan number? explain

Ramanujan  number is 1729.

 When a number is multiplied by itself the answer is called a “square”, e.g. 3x3=9, so the number 9 is a square.

    When a number is multiplied three times by itself the answer is called a “cube”, e.g. 3x3x3=27, so the number 27 is a cube.

    Another example of a cube is 8, because it is 2x2x2.

    27+8=35, so 35 is the “sum of two cubes” (“sum” in this sense means “numbers that are added together”).


There are two ways to say that 1729 is the sum of two cubes. 1x1x1=1; 12x12x12=1728. So 1+1728=1729
But also: 9x9x9=729; 10x10x10=1000. So 729+1000=1729
 the sum of two cubes in more than one way, but 1729 is the smallest of them.


comments powered by Disqus