113M 3G/4G phones sold in 2016. The ten South East Asian countries have a population of 625 million, nearly twice as many as the United States. By some measures, they will soon have more Internet users than the U.S. Indonesia, the Philipines, Thailand, Malaysia, and Singapore have more SIM subscription than they have people. Mobile is exploding in Myanmar, which will soon join that group.
There are probably only 350-400M mobile subscribers; dual SIM phones and other factors explain the discrepancy. Digitimes's 60% smartphone estimate is for the end of this year, up from 46% in 2015.