nonillion vs septillion

nonillion

num

  • 10³⁰. 

  • 10⁵⁴. 

noun

  • An unspecified very large number. 

septillion

num

  • A billion quintillion: 1 followed by 42 zeros, 10⁴². 

  • A trillion trillion: 1 followed by 24 zeros, 10²⁴. 

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