It was large symbolic number like you or I saying "gazillions" or "tons" but it was Rome's army at full force that had surrounded the city and temple and SLAUGHTERED practically everyone and destroyed the temple, walls, and city for the most part.

There were also joined by the host of hell and there are even secular accounts of the horror that happened in the city as God's judgment came upon it. Straight demonic horrors that sound like they were poured out of bowls.