142857 is the number

142857 which added for six times will give only the six digit answer and added for the seventh time will give the answer 999999 - all nines.

i. 142857+142857=285714
ii. 142857+142857+142857=428571
iii. 142857+142857+142857+142857=571428
iv. 142857+142857+142857+142857+142857=714285
v.142857+142857+142857+142857+142857+142857=857142
vi. 142857+142857+142857+142857+142857+142857+142857=999999