Your height number is off by a factor of 2; a significant factor of container storage on these large container ships is below the deck. It isn't uncommon for these large ships to have 9 to 12 containers stacked on top of eachother before the stack reaches above the deck and becomes visible from the side.
It appears to be roughly 7 x 20 x 25 containers, or 3500... (height x width x length.)
EDIT: Freezing this video I got a better view of how it's stacked today. I'm sure this is imperfect, like I said trying to count candy in a jar. But I'm curious what the real number of containers is!
H X W X L
10 X 23 X 25 ~= 5750
https://www.reuters.com/article/us-egypt-suezcanal-ship/beac...