Checks if a value is a number and returns TRUE or FALSE.
This function works the same in Google Sheets as it does in Excel — same syntax and arguments.
ISNUMBER(value)The ISNUMBER function determines whether a given value is a numeric type. It returns TRUE if the value is a number, and FALSE if it is text, an error, or another data type.
=ISNUMBER(123)Result: TRUE
Returns TRUE because 123 is a numeric value.
=ISNUMBER("Excel")Result: FALSE
Returns FALSE because the input is a text string.
No, ISNUMBER returns FALSE for numbers stored as text strings.