Using divisibility tests, determine the following number is divisible by $$4$$; by $$8$$.
$$21084$$.
$$21084$$ is divisible by $$4$$ because the number formed by the last two digits $$(84)$$ is divisible by $$4$$.
$$21084$$ is not divisible by $$8$$ because the number formed by the last three digits $$(084)$$ is not divisible by $$8$$.