This is the spreadsheet to prove this constant. When all roads lead to Kaprekar
Just enter any 4 digits number in D3 and watch roads walk you 6174
Category: VALUE
VALUE() of LEFT()
I have been in a lot of situation needing to convert a number came out from a string into actual numbers. Sometimes N() worked, sometimes not, others VALUE() worked, but I did not see a function-does-all solution.