Great post!
To clarify: IOTA is the official term for one unit of IOTA, I think there might rise some confusion if we don't clarify this.

Indeed the total circulating supply of IOTAs indicated in MIOTA.

They use the international SI nomenclature to indicate units of IOTA. currently the tradable unit is 1 Mi.

(Ki), KiloIota, kIOTA = 1.000 units
(Mi), MegaIota, MIOTA = 1.000.000 units
(Gi), GigaIota, GIOTA = 1.000.000.000 units
(Ti), TeraIota, TIOTA = 1.000.000.000.000 units
(Pi) PetaIota, PIOTA = 1.000.000.000.000.000 units

Keep this in mind when exploring IOTA.

Greetings!