This is the 4088th most frequent Russian word.
организаторами
"By the organizers" or "with the organizers" (instrumental plural of "организатор").
The word "организаторами" here indicates the role of the persons who were responsible for organizing the event and is used as an instrumental plural noun to describe the actors performing the action.
Мероприятие было организовано опытными организаторами.
The event was organized by experienced organizers.
In this sentence, "организаторами" is used in the instrumental case to indicate the role of the people who facilitated the meeting, emphasizing their function in the interaction.
Встреча с организаторами дала нам полезные советы.
The meeting with the organizers gave us useful advice.
Here, "организаторами" is used again as an instrumental plural noun to specify the individuals the interaction was carried out with.