IsNumeric()

Returns a Boolean value indicating whether an expression can be evaluated as a number.

IsEmpty()

The IsEmpty function returns a Boolean value that indicates whether a single cell is empty: True if empty, False if not. The cell must truly be empty for the function to return True. If it contains even just a space that you cannot see, Excel does not consider the cell to be empty.

IsDate

Returns True if the expression is a date or is recognizable as a valid date or time; otherwise, it returns False.

IsError

Returns a Boolean value indicating whether an expression is an error value.