13-Letter Words Matching ____A____O___

There are 16 13-letter words that match ____A____O___. 2 are common words, such as PHILANTHROPIC and SUPRANATIONAL. A rarer one is ULTRARATIONAL. In this set, L is the most frequent open letter (15 words). 2 words contain a doubled letter.

Full list 16

philanthropicsupranationalcephalothoraxmethaqualonesuntraditionalcephalosporinextrasystolesgalvanoscopesintrapersonallollapaloozasnoncarcinogenpreganglionicsuprarationaltetrapyrrolesultraorthodoxultrarational

About this list

Words
16 (2 common words)
Common example
philanthropic
Rare example
ultrarational
Doubled letters
2
Ending in S
5
Most frequent letter
L (15)

Questions

How many 13-letter words matching ____a____o___ are there?

16. 2 of them are common words.

What is a common example?

PHILANTHROPIC is among the common words in this set.