In excel if I increase the indent more than 7 decimal digits showing the value: 55156180.4400003000000
but with increasing the indent to only 6 digits shows:55156180.440000

What could be the reason and how to resolve this issue.
Request any suggestions.

I don't understand the problem.

IF the number is 55156180.4400003000000 and you format that to 6 decimals, the rounding results in 55156180.440000 because the 3 in the 7th decimal isn't high enough to cause it to round up.