Definition:Kaprekar's Constant

Definition

Let $n \in \Z_{>0}$ be a positive integer with $4$ digits, not all of which are equal.

Let Kaprekar's process be applied to $n$.

The number reached after no more than $8$ iterations is known as Kaprekar's constant, and has the value of $6174$.

Source of Name

This entry was named for Dattathreya Ramchandra Kaprekar.

Sources

• 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $6174$
• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $6174$

• Weisstein, Eric W. "Kaprekar Routine." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/KaprekarRoutine.html