Series for 2-digit numbers

There is only one series for 2-digit numbers - 9 -> 81 -> 63 -> 27 -> 45 -> repeat

Series for 3-digit numbers

There is one Kaprekar Constant for 3-digit numbers - 495.

Series for 4-digit numbers

There is one Kaprekar Constant for 4-digit numbers - 6174.

Series for 5-digit numbers

There are three series for 5-digit numbers -

   74943 -> 62964 -> 71973 -> 83952 -> repeat

   63954 -> 61974 -> 82962 -> 75933 -> repeat

   53955 -> 59994 -> repeat

Series for 6-digit numbers

There are two Kaprekar Constants for 6-digit numbers - 631764 and 549945. And there is one series -

   851742 -> 750843 -> 840852 -> 860832 -> 862632 -> 642654 -> 420876 -> repeat

Series for 7-digit numbers

There is only one series for 7-digit numbers -

   8429652 -> 7619733 -> 8439552 -> 7509843 -> 9529641 -> 8719722 -> 8649432 -> 7519743 -> repeat

Series for 8-digit numbers

There are two Kaprekar Constants for 8-digit numbers - 97508421 and 63317664. And there are two series -

   86526432 -> 64308654 -> 83208762 -> repeat

   86308632 -> 86326632 -> 64326654 -> 43208766 -> 85317642 -> 75308643 -> 84308652 -> repeat

Series for 9-digit numbers

There are two Kaprekar Constants for 9-digit numbers - 864197532 and 554999445. And there is one series -

   865296432 -> 763197633 -> 844296552 -> 762098733 -> 964395531 -> 863098632 -> 965296431 -> 873197622 -> 865395432 -> 753098643 -> 954197541 -> 883098612 -> 976494321 -> 874197522 -> repeat

Series for 10-digit numbers

There are three Kaprekar Constants for 10-digit numbers - 9753086421, 6333176664 and 9975084201. And there are five series -

   8655264432 -> 6431088654 -> 8732087622 -> repeat

   8653266432 -> 6433086654 -> 8332087662 -> repeat

   8765264322 -> 6543086544 -> 8321088762 -> repeat

   8633086632 -> 8633266632 -> 6433266654 -> 4332087666 -> 8533176642 -> 7533086643 -> 8433086652 -> repeat

   9775084221 -> 9755084421 -> 9751088421 -> repeat

More Kaprekar Series Numbers: (11-digit to 20-digit).