I know that the other way is not true, i.e:
If an address is 8 byte aligned it's not necessary 16 byte aligned. An example is 8
itself.
8 is not divisible by 16.
But I'm guessing every number divisible by 16 should also be divisible by 8, in which case if an address is aligned to 16 bytes, it is also aligned to 8 bytes correct?