Which number replace question mark in the series?

16 8 40 20 100 50 250 ? 625

16 8 40 20 100 50 250 ? 625

125
Explanation: (alternate series of /2 and &5)
16/2 = 8
8 * 5 = 40
40/2 = 20
20 * 5 = 100
100/2 = 50
50 * 5 = 250
250/2 = 125
125 * 5 = 625