Given by D.R. Kaprekar (1905-1988) : Fond of numbers. Well known for "Kaprekar Constant" 6174.
Procedure to arrive Kaprekar Constant:
1. Take any four digit number in which all digits are not alike.
2. Arrange its digits in descending order and subtract from it the number formed by arranging the digits in ascending order.
3. If this process is repeated with reminders, ultimately number 6174 is obtained, which then generates itself.
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