This is a belated reaction to the statement on a recent show that one million microphones equal a megaphone. In the usual parlance, one million microphones would be a phone; a million million microphones, or a million phones, would be a megaphone.
Interesting catch. It is an exercise in semantics I suppose, as I don’t think it takes a million microcars to equal one car. Glad to see someone is thinking, fun!
Gotta love the metric system!
It was a joke. It can be anything the teller wants it to be as long as it gets a laugh! 
A million microphones isn’t a phone…it’s a million microphones. “Microphone” is a nomenclature, an improper noun. There is no correct term for a million of them other than…a million of them.
Similarly, a million tomatoes isn’t a megatomatoe…it’s just a million tomatoes.
So a bug with 1000 legs isn’t a megapede?
Nope. A bug with a MILLION legs is a megapede!
But a half million bugs with two legs each isn’t a megapede…it’s a half million two legged bugs.
I have a special telephone on its own line to book musical engagements. This telephone is called a gigaphone.
Gigaphone…I like that.
CORRECTION: a half million two legged bugs is a half million bipedal bugs!
I don’t think there’s any such thing as a bipedal bug - unless some obnoxious kid pulled a bunch of its legs off. I think only two legs disqualifies it from the bug category. But if there were bipedal bugs then I give the argument to mountainbike.
But wait…if by a “bug” we mean a tiny little microphone…
Cig, I was wondering when someone would catch that.
Where’s that retired linguistics professor when you need him?