https://skeptics.stackexchange.com/a/36111/32459 says:
The name Muhammad actually appears in the Qur'an only four times, and in three of those instances it could be used as a title – the "praised one" or "chosen one" – rather than as a proper name. Source: Did Muhammad Exist? (2012), p. 17
it is from http://www.americanthinker.com/articles/2012/04/inventing_muhammad.html
is it true?