~459,530
To put that in perspective, here's a picture of Ferenc Puskas Stadium in Budapest (I couldn't find a decent one of Wembley) which although demolished now held a capacity of 67,155 with the largest attendance supposedly right on 104,000 back in 1956 (no Health and Safety regs back then!)
So that number: ~459,530 is
somewhere between 6 and 7 times what you see in this picture (plus the bits you don't see because they're out of view)
