Final answer:
There are 1,048,576 5-topping pizzas possible.
Step-by-step explanation:
To find the number of 5-topping pizzas possible, we need to consider the number of choices for each topping. Since the pizza parlor offers 16 different toppings, we have 16 choices for the first topping, 16 choices for the second topping, and so on. So, the total number of 5-topping pizzas possible is calculated by multiplying the number of choices for each topping: 16 x 16 x 16 x 16 x 16 = 165 = 1,048,576.