6174

A crazy number.

Take any four digit number with digits that aren't all the same (2354, 2009, 7162) and order the digits from biggest to smallest and then from smallest to biggest.

Subtract the smaller number from the bigger one. Take that number and repeat.

Once 6174 shows up, you can't go any further.

We'll use 2009 for this.

So we have 9002 and 0029 (or 29)

9002-29=8973 (so 9873 and 3789)
9873-3789=6084(8640 and 3789)
8640-468=8172
8721-1278=7443
7443-3447=3996
9963-3699=6264
6642-2466=4176
7461-1467=6174
7461-1467=6174
7461-1467=6174
it will keep repeating itself.

by 6174 April 5, 2009