In the early 2000s. Page Rank isn’t a publicly available factor anymore according to Google. You can monitor your page and domain using other metrics such as Domain Authority, Citation Flow and Trust Flow. These metrics are 3rd party measures of what they expect Google to see your site as for ranking keywords. They are not Google’s metrics. There are additional competing metrics from other sites as well and you should be aware of them all. Test them out and decide for yourself which numbers work best for you.
Ultimate SEO uses Domain Authority and Trust Flow along with Spam Score to help build a base depectition of a page’s ability to rank a keyword.