數目字轉英文

It should be written as "One million eight hundred and six thousand seventy nine Hong Kong dollars".

If you wanna learn how to write it quickly, actually there is a way to.

The coma (",") in between the numbers actually has its use and meaning.
It groups the numbers together.

From right hand side to left hand side,
for the first 3 digit, it is name of integer to hundred;
then for the next 3 digits, its kinds of "thousand" like "e.g. six hundred / sixty / six thousand";
then it arrived to "million" for next 3 places, billion for the futher 3 more places.

Actually there should be some more words to describe the numbering, but they're seldom used as billion is already 十億 in chinese.

Nevertheless, I need to remind you, "and" used in numbering should only be appered once.

One Million Eight Hundred Six Thousand and Seventy Nine Dollars

One million eight hundred and six thousand and seventy-nine Hong Kong Dollars (寫支票要加 Only .)

Hong Kong Dollars One Million Eight Hundred Six Thousand and Seventy Nine Only.