This cannot be answered properly because at least two numbers are required.
54 is.
54
It is 54
54
54
It is: 1080
LCD(54, 24) = 216
That's the least common denominator or LCD.
The least common denominator.
There can be no greatest common denominator. If you have a set a numbers whose least common denominator is L then 2*L, 3*L, … are all common denominators. There is no end to that sequence and so no greatest.
The least common multiple of two or more denominators is known as the least common denominator, or LCD.
The least common denominator is the least common multiple of the denominators of the fractions.