They don't have any statistics available on DMNXF in otcmarkets.com but I found an outstanding share count of 3.4B listed on YF. I rounded up to get 5B since there are usually alot of options and/or warrants on an issue like this. I also checked CNBC which lists 2.5B shares outstanding.
I'm not claiming that data on YF or CNBC is always correct but I'd doublecheck if I were you.