Increasing page rank of website does not depend on any particular number of backlinks.
Although backlinks are necessary from quality sites but What remains important is concentrating on your websites ON-Page and OFF-Page SEO with good content.
It's only depends on the keyword competition that how many back links you should do for your website in order to come in the first page of Google. Also you can research your competitors how many back links they have.
@rosario1990 I guess you are taking things in towards a different perspective you can't say that if you have a large number of backlinks then you can rank over the first page of Google, rather than there are anumber of other factor that Google looks onto before ranking you over the SERPs! So, following only the link path isn't a good idea at all !
You'll need a lot but they should be of quality. I may advise you to search different websites and explore their high authority pages, in this way, you can generate quality links for your website, otherwise, you can also buy backlinks of high PR from sites like SEoclerks.
You don’t need thousands or even hundreds of backlink for better ranking because Google has changed its algorithm from quantity, to quantity and quality. But quality is more important now.In fact, you can make it to the first page of Google with just a few backlinks