incommensurable vs relatively prime

incommensurable

adj
  • having no common integer divisor except 1. 

  • Not able to be measured by the same standards as another term in the context. 

  • having a ratio that is not expressible as a fraction of two integers. 

noun
  • An incommensurable value or quantity; an irrational number. 

relatively prime

adj
  • having no factors (except the number 1) in common with a specified other number or numbers. 

  • having no factors (except the number 1) in common. 

How often have the words incommensurable and relatively prime occurred in a corpus of books? (source: Google Ngram Viewer )