There is none because Least Common Denominator (or LCD) refers to the Least Common Multiple (LCM) of the denominators of two or more fractions or mixed numbers. Even if you converted your whole numbers (x) to their fraction equivalents (x/1), the LCD would always be 1.
144
The Least Common Multiple (LCM) for 18 32 48 is 288.
The least common denominator for 12 and 16 is 48.
A common denominator, though the least, is 48.
48