MapInfo Pro: LargeInt fields are being read as Characters in MapInfo Pro.

MapInfo 12.5, 16.0, 17.0
We do not support Large Integer via the GUI (Graphical User Interface). It can be used via MapBasic where this will work.

In MapBasic you can create a table with LargeInt and you can use dim LargeInt variables, too.

Please refer to the MapBasic guide for more information.
UPDATED:  April 6, 2020