There are 17 information functions varying in usefulness, power and potential complexity.

Data Type Information Functions

Function Usefulness Power Complexity
ISBLANK
ISLOGICAL
ISNONTEXT
ISREF
ISTEXT
TYPE

Error Information Functions

Function Usefulness Power Complexity
ERROR.TYPE
ISERR
ISERROR
ISNA

Numerical Information Functions

Function Usefulness Power Complexity
ISEVEN
ISNUMBER
ISODD
N

Constant Information Functions

Function Usefulness Power Complexity
NA

Other Information Functions

Function Usefulness Power Complexity
CELL
INFO
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Using a Information function:
Using a Information Excel function

Summary

Excel's information functions are primarily used to get information about cells, ranges and worksheets and can play a role in managing errors in your workbook or as inputs to other formulas.