Why other digit lengths behave differently
Kaprekar’s operation acts on a finite set of fixed-width digit strings. Because the rule is deterministic, every path must eventually revisit a value. A repeated value either maps to itself—a fixed point—or closes a loop containing several values. The celebrated four-digit result is special because all non-repdigit decimal inputs share the 6174 destination; that pattern is not guaranteed when the width changes.
Use the selector to compare widths from two to six digits. Leading zeroes remain part of the state at every step, and the explorer stops as soon as it detects the first repeated state rather than printing the loop forever.
Learn about fixed points and attractors →