Access cell reference of first cell in column to fulfill a condition?

I have a certain column in my spreadsheet whose entries' datatypes exist in the pattern:

alphanumeric
alphanumeric
.
.
.
alphanumeric
numeric
numeric
numeric
.
.
.

and stay strictly numeric from that row onward. Is there a way to obtain the cell reference (specifically row number, but that is trivial to get with ROW() once the reference is acquired) of the first cell that contains strictly numeric data?

Blanks may also appear at any point(s) in the column.