This is the 6888th most frequent Russian word.
азербайджаном
The word "азербайджаном" is the instrumental case of "Азербайджан" (Azerbaijan), meaning "with/by Azerbaijan" in English.
Here, 'Азербайджаном' is in the instrumental case, used after 'по' to indicate a region being traveled through.
Она путешествовала по Азербайджаном в прошлом году.
She traveled through Azerbaijan last year.
In this usage, 'Азербайджаном' is in the instrumental case, signifying a relationship or connection with Azerbaijan.
Мы дружим с Азербайджаном уже много лет.
We have been friends with Azerbaijan for many years.
In this sentence, 'Азербайджаном' is used in the instrumental case, denoting a relation or association with Azerbaijan.