What's special about the number 6174?
Have you heard of the 'Kaprekar Constant' - 6174? Basically, is you take 4 numbers and create two 4-digit numbers - one with them in ascending order and the other in descending order, and if you perform the Kaprekar Routine (subtract the smaller from the larger) then, within 8 iterations, you will end up with 6174. Try this out... It's amazing!