Number Series - General Questions

Look at this series: 20, 55, 22, 52, 24, 49, … What number should come next?

Look at this series and find the number that does not belong: 1, 3, 9, 28, 81, 243, 729

Look at this series: 47, 53, 59, 61, 67, 71, … What number should come next?

Look at this series and find the number that does not belong: 4, 5, 9, 14, 23, 39, 60

Look at this series and find the number that does not belong: 4, 7, 16, 32, 64, 128, 256