Passengers in flight at one time

[Scott Summers]

Not sure if this is the proper area to post this question - but
someone told me the other day - that at any given time, there are at
least one million passengers on airplanes in the skies.

I thought this number was unusually high. But then I thought about it
and it started to make sense.

Can anyone confirm or deny if this is an accurate statement?

Thanks!