The ISNUMBER Function is to check whether a value is a number. The result returns TRUE when it is a number.
Formula:
=ISNUMBER(value)
Explanations:
Value is required, the result returns TRUE when the value is a number and returns False when it is not a number.
Example:
=ISNUMBER(A1)
Cell A1 is a logical value, not a number, so ISNUMBER(A1) returns False.
=ISNUMBER(A3)
Cell A5 is 8, a number, so ISNUMBER(A3) returns True.