This is the 2717th most frequent Russian word.
вячеслава
"Вячеслава" is a Russian female name, meaning "greater glory."
The name 'Вячеслава' is used here as a proper noun indicating a person's name in the accusative case, denoting the direct object of the invitation.
Вячеслава пригласили на концерт.
Vyacheslav was invited to the concert.
The name 'Вячеславе' is in the dative case here, showing it as the indirect object of liking the book.
Мы обсуждали книгу, которая понравилась Вячеславе.
We were discussing the book that Vyacheslava liked.
Here, 'Вячеслава' is in the genitive case, used to indicate possession of the book.