This function tests whether a value, an expression, or contents of a referenced cell has numeric data.
ISNUMBER(cellreference)
ISNUMBER(value)
ISNUMBER(expression)
Specify a cell reference, a numeric or text value, or an expression for the argument.
Use this function to test the contents of a cell, a numeric or text value directly, or a function or expression.
This function returns TRUE if the argument is or refers to a number, and returns FALSE if the argument is or refers to a value that is not a number. This function returns FALSE if the value is or refers to a cell with no data.
You might want to use this function to test whether cells contain numeric data before you perform mathematical operations on them, such as averaging the contents of a range of cells.
Accepts any data type for an argument. Returns Boolean (TRUE or FALSE) data.
ISNUMBER(B3)
ISNUMBER(R1C2)
ISNUMBER(12) gives the result TRUE