# What is the significance of the number "1729"?

This is Srinivasa Ramanujan's Lucky Number

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• Kes
Lv 7

Hardy's dull number Ramanujan's interesting (and lucky?) number.

It is the first number that can be expressed as sum of cube of 2 different set of 2 numbers

12^+1^3=1728+1=1729

9^3+10^=729+1000=1729

Source(s): none
• Jimbo
Lv 5

I have no idea except 1729 = 1000+729 = 10^3 + 9^3 = 19 x 91 = 19 x13x7. So it is a bit interesting since two of its factors are 7 and 13. Also, 29-17= 12 and 12^3 = 1728, and 10^3+9^3 =12^3 +1^3. He liked number theory.

It is the sum of cube of 9 & cube of 10. (9^3 + 10^3 = 1729)

1 x (7+2) = 9

• Anonymous

1 is the fact you are first as in being #1. 7 is the old lucky number to gamble on. 2 is how many it takes to tango, and 9 is what you get when you add 2 that are getting lucky (7) and nine is the outcome of the addition.

It was the number of the cab used by Hardy when he came to visit Ramanujan, and became a topic of conversation between the two.

This is the smallest number that can be expressed as sum of 2 cubes in 2 different ways(10,9) and(12,1)

• Gayle
Lv 4
4 years ago

Agree