EVEN( ) And ODD( )

EVEN( ) and ODD( ) are the last of Excel's rounding functions. These functions accept a single number and round it up to the nearest even or odd number. As simple as this sounds, these functions can cause a bit of confusion because many people assume that the functions will return the closest odd or even number. But they don't. Since the functions round up, the closest correct number may be, numerically speaking, a confusingly long ways away.
To understand these quirky functions a little better, consider the following formula: =ODD(2.6)

This formula produces the expected result: It rounds 2.6 up to the closest odd number, 3. Now consider: =ODD(3.6)

This formula also rounds up to the nearest odd number, which in this case is 5.
In fact, ODD( ) always rounds up, unless you begin with a whole odd number. That means that the result of the following formula is also 5, even though 3.1 is clearly much closer to 3 than 5: =ODD(3.1)

The EVEN( ) function behaves similarly. Thus, the result of the following formula is 4: =EVEN(2.1)

The EVEN( ) and ODD( ) functions aren't useful too often. For most people, they simply represent an interesting footnote in Excel functions.