| ISLOGICAL | Checks if the value is logical. Returns TRUE if it is and FALSE if not | ISLOGICAL(value) |
| ISNA | Checks if the value is the error #N/A (value not available). Returns TRUE if it is and FALSE if not | ISNA(value) |
| ISODD | Checks if the value is an odd number. Returns TRUE if it is and FALSE if not | ISODD(value) |
| ISERR | Checks if the value is an error other than #N/A (value not available). Returns TRUE if it is and FALSE if not | ISERR(value) |
| ISERROR | Checks if the value is an error. Returns TRUE if it is and FALSE if not | ISERROR(value) |
| ISBLANK | Checks if the cell is empty. Returns TRUE if it is and FALSE if it contains any data (including spaces, hidden characters and empty strings) | ISBLANK(value) |
| ISREF | Checks if the value is a cell reference. Returns TRUE if it is and FALSE if not | ISREF(value) |
| ISTEXT | Checks if the value is text. Returns TRUE if it is and FALSE if not | ISTEXT(value) |
| ISEVEN | Checks if the value is an even number. Returns TRUE if it is and FALSE if not | ISEVEN(value) |
| ISNUMBER | Checks if the value is a number. Returns TRUE if it is and FALSE if not | ISNUMBER(value) |
| NA | Returns the error value #N/A (value not available) | NA() |
| CELL | Returns the information about the cell | CELL(info_type, [reference]) |