That is Pega’s OOTB functionality to sort text properties like this. You can try to run the report from a data page where in the response data transform, perform a sorting on Primary.pxResults.
@kirti - Can apply formatting on the report definition at the column level by clicking on the gear icon. Add pxDisplayText and click on search icon and set the fields as number.
@kirti - Can you please brief about the structure how your are accessing the records on the screen i.e. on a table sourced to pagelist and referred to data page… something in these lines.