I haven't read book but was attracted by title. First 30 mins was good. Such promise. Sadly after that it was a complete waste of time. Rather than spend time writing a further review I can say Mendhak's review perfectly sums it up: "a jumble of time-lines and a storyline filled with teenage angst and pointless drama. It is also full of needlessly prolonged scenes that make no sense, but which you can feel the director congratulated himself over. Also, this movie has nothing to do with prime numbers. Prime numbers may have been mentioned in one or two sentences in the movie, but were never the focus. I wonder if there was a better reason in the book for using the words 'prime numbers'. " Don't waste your time on it...even the cinematography descended into rubbish after first 30 mins....