Calculating the number of address lines needed for a memory in 3-dimensional memory array

Using address multiplexing where the address lines are used by the row and column selector of a 3-dimensional memory array with the third dimension being 8 bits, how many address lines are needed for a memory with a bit capacity of 524288 bits?

My approach:
begin{align*} M &= log_2left(dfrac{524288}{8}right)\ &= log_2(65536)\ &= 16 end{align*}
Is is 16? Or I’m supposed to divide it by 2 since we are using address multiplexing? I’m confused.