There are none. The lowest multiple of 21 is 21.
there are 21 multiples.
21,42,63,84
Nine: 7, 14, 21, 28, 35, 42, 49, 56, 63.
21, 42, 63, 84.
21,42,63,84
21: 21, 42, 63, and 84!
21, 42, 63, 84
21, 42, 63, 84.
63
Just 63.
Just 63.
They are: 21, 42, 63 and 84