This is the 12104th most frequent Swedish word.
rikaste
"Rikaste" means "richest" in English.
'Rikaste' is used here as a superlative adjective describing 'man', showing he has the highest amount of wealth.
Han är den rikaste mannen i staden.
He is the richest man in the city.
'Rikaste' in this sentence is part of the phrase 'en av de rikaste', indicating comparison among a group, with 'rikaste' still as a superlative.
Jag önskar att jag vore en av de rikaste personerna.
I wish I were one of the richest people.
'Rikaste' is used here to describe the comparative superlative property of 'företaget', indicating great wealth among companies.