Zhè chǎng dìzhèn zàochéng chéngbǎiwàn de rén wújiā kě guī.
The earthquake left millions of people homeless.
Tips
usage
成百万 is used before a noun to emphasize a very large number in the millions. Compare 成千上万 (tens of thousands; vast numbers), which is far more common. 成百万 is somewhat less idiomatic — 数以百万计 is a more formal alternative.