Why is 16 a multiple of 1 4 and 16?

16 is a multiple of 1 because 1 x 16 = 16

16 is a multiple of 4 because 4 x 4 = 16

16 is a multiple of 16 because 16 x 1 = 16

16 is the LCM of that set of three numbers because there is no smaller number that is a multiple of those three.