Offer factorials and other integer numbers as unsigned long, etc.

Offer factorials and other integer numbers as unsigned long, etc.
Look at the templates and see if we can do it now.
You might go ahead and do the C thing with ull/ul or ll/l suffixed things.

Start by inspecting the project templates to determine how factorials and other integer-valued functions currently select return types. Define the required unsigned-long and related C-style suffix variants, including ull, ul, ll, and l, and consider how completion will be verified across the affected functions.

Written by the indexing model from the issue text.