What's the missing term in these two sequences?

45, ___, 1620,.


25, ___, 900,.

Notice that

45 = 45 \cdot 6^0

??? = 45 \cdot ???

1620 = 45 \cdot 6^2

and

25 = 25 \cdot 6^0

??? = 25 \cdot ???

900 = 25 \cdot 6^2

Now can you fill in the missing numbers?