What is the last digit of:
$2^{24!}$
I am not sure how to approach this problem as 24! is extremely large. Normally I would notice the cyclic nature of powers of 2 i.e. $2^1 = 2, 2^2 = 4, 2^3 = 8, 2^4 = 16, 2^5 = 32$ and so the last digit cycles so all we need to do is determine $n$ mod $4$.
But not sure how to do it with such a large number, thanks.