Pls help me to solve this tricky question really confusing!!!

can u find a number which added to itself one or several times will give a total having the same digits as that number but differently arranged and after the sixth addition will give a total of all nines?
pls explain with steps

If I understand the question correctly, 6 additions means 7 times the original number. And the solution is the 6 digits which are present in the decimal representation of 1/7:

142857
285714
428571
571428
714285
857142
999999

And it also works if you extend the number:
e.g. use 142857142857, 142857142857142857, etc