Mike H wrote...
Try this

=COUNTA(A1:A6)-COUNT(A1:A6)
....

This counts all entries except numbers, which means it'd count boolean
and error values in addition to text.

Simplest way to count cells containing text is

=COUNTIF(range,"*")

which would include nonblank cells evaluating to "". To count only
text with one or more characters, use

=COUNTIF(range,"?*")