Words that contain 'r' and end in 'ium'

Which word that has 'r' in and ends with 'ium' is the most common word?
There's 'delirium', which ranks as the 13877^th most popular word.

What's the highest number of points you're able to get in Scrabble from this list of words containing 'r' and ending with 'ium'?
Since there are so many words to pick from, we would recommend opting for 'aquarium' which scores 19 points overall.

How many words could one make using this combination of letters?
One could derive 889 words with the specified combination.

What is an interesting word from all the word combinations possible ?
Our favorite strange word from this list is 'solarium'. According to the Oxford dictionary, 'solarium' means "1. An apartment freely exposed to the sun; anciently, an apartment or inclosure on the roof of a house; in modern times, an apartment in a hospital, used as a resort for convalescents. 2. (Zoöl.) Any one of several species of handsome marine spiral shells of the genus Solarium...".

Which word on this page has the highest character count?
The word 'hydropneumopericardium' contains 22 characters.