[chgs]

And some counties group numbers in twos rather than threes - 1,23,45,678.90

International standard is space for separators - 1 000 000. That’s a pain on a phone.

[isametry]

Figure space to be specific (U+2007 or &numsp). A plain space like in your million will break across lines.

(And yes, that’s even more of a pain on a phone.)