63
7 times 3 times 3.
6 + 3 = 9
63
3
Any multiple of 21.
84
119
LCM: 42
The LCM is: 210
3 * 7
Common three-digit multiples of 27 and 11 are 297, 594 and 891. None of their digits add up to 10.
The LCM is: 54
No factor of 9 has three digits. 450 is a three-digit multiple of 150 (and of 9) with a digit sum of 9.
If the sum of the digits is a multiple of three, the whole number is a multiple of three.