Let me first tell about the calculation behind that. Google says that page rank calculation formula is having more than 2 lakh variables. I am sure that following things are the main factor,
1) Internal Back Links
2) External Back Links
3) Domain Age
Apart from this, number of visits, bounce rate, CTR etc may be a factor in calculating the page rank. Page rank is just a metric from Google which defines the quality of the page. Moreover we do have many other targets like keyword position, quality traffic and conversions. In my vision, I am having very least importance to page rank.