6174 - Numberphile
6174 is also known as Kaprekar's Constant. More links & stuff in full description below ↓↓↓ This video features University of Nottingham physics professor ...
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MALE SPEAKER 1: The number I want to talk about is 6,174. And it doesn't seem to have anything which is unusual about it. But Kaprekar showed that if you carry out a procedure, which I'll outline for you, it always comes to this number. The conditions are that it has to have four digits and these four digits mustn't be the same. So you have to choose maybe three the same and one different. Or all different. It doesn't really matter. But you don't choose 1, 1, 1, 1 or 0, 0, 0, 0. So I asked you to choose one at random and you said 9,218 is your starting point. Now the first thing you do with this is to put that in the order, the largest number first, then the next largest number, then the next largest number, and then the smallest. And then the other way ...
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MALE SPEAKER 1: The number I want to talk about is 6,174. And it doesn't seem to have anything which is unusual about it. But Kaprekar showed that if you carry out a procedure, which I'll outline for you, it always comes to this number. The conditions are that it has to have four digits and these four digits mustn't be the same. So you have to choose maybe three the same and one different. Or all different. It doesn't really matter. But you don't choose 1, 1, 1, 1 or 0, 0, 0, 0. So I asked you to choose one at random and you said 9,218 is your starting point. Now the first thing you do with this is to put that in the order, the largest number first, then the next largest number, then the next largest number, and then the smallest. And then the other way ...
