NaN (Not a Number) is a value that is usually returned as the result of an operation on invalid input operands, especially in floating-point calculations. For example, when an operation attempts to divide zero by zero, it returns a NaN result.

Operating systems and programming languages may represent NaN differently. For example the following list shows valid string representations of NaN:

The Integration Service converts QNAN values to 1.#QNAN on Win64EMT platforms. 1.#QNAN is a valid representation of NaN.