With the Verizon iPhone announcement coming on Tuesday, analysts are trying to figure out how many iPhones the company will sell. One analyst pegs that number at 9 million.

[ad#Google Adsense 300×250 in story]In a research note to clients on Monday, Piper Jaffray Senior Research Analyst Gene Munster said he expects Apple to sell 20 million iPhones in 2011. That breaks down to 11 million for AT&T and 9 million for Verizon.

Keep in mind these are just the sales at the wireless carriers, not the total number of iPhones sold. Apple also sells the device online and at its own retail stores.

Munster also said he estimates that the 5.2 million iPhones sold by AT&T in the September 2010 quarter represented about 80 percent of all smartphones sold by AT&T. That leaves 20 percent for Android, Blackberry, Palm, Symbian and Windows 7.