This is simply default Excel behaviour. Numbers that are very long (such as 447787574382) are represented in exponential notation.
The solution to this is to: do the conversion, then select ALL the numbers from number column and then right click on them and choose “Format Cells” option. Then instead of “General” choose “Number” and set number of decimal places to 0.
This article refers to Able2Extract and Able2Extract Professional.