How would I do it with Physical Quantities?
I tried this, but it didn't work.
constants =
EntityClass["PhysicalQuantity",
All][{EntityProperty["PhysicalQuantity", "Name"],
EntityProperty["PhysicalQuantity", "Value"]}];
Grid[ReverseSortBy[
With[{un = QuantityUnit@UnitConvert[#2]}, {#1, #2, un,
Length[Cases[un, _String, All] /.
"DimensionlessUnit" -> Nothing]}] & @@@ constants, Last],
Frame -> All]
[@Henrik Schachner][at0]