Honorable History on Instagram: "6174, known as Kaprekar’s Constant, is uniquely magical in base 10. Take any four-digit number (not all digits identical). Arrange digits to form the largest and smallest possible numbers, subtract the smaller from the larger, and repeat with the result. Within at most 7 steps, you always reach 6174. Then, it cycles forever: 7641 − 1467 = 6174. No other number attracts all such inputs. For three digits, 495 works similarly, but longer numbers produce cycles, not