Can I find my IMEI number of my lost iPhone using my iCloud account?

No but you may be able to find your iPhone using iCloud if by chance you didn't install the Finder My iPhone app.

See: "If Find My iPhone isn't enabled on your missing device" > What to do if your iOS device is lost or stolen

Devices are found by location, not IMEI.

The IMEI may also be in iTunes on your computer. It is certainly on your iPhone's box (the original box from the factory).

See:

Find the serial number and other information for your iPhone, iPad, and iPod touch - Apple Support