ISMISSING function
Description
Cell-is-missing function. ISMISSING(var) returns the logical value 1 (=TRUE) if the calculation of var does not result in a numeric or text value, or var equals a user-defined missing value (see USRMISSING function).
Examples
ISMISSING(B2) returns 0 (=FALSE) if cell B2 contains a number or a string value, e.g. "SMITH".
ISMISSING(25.6) returns 0