^^^ With 8 billion people on Earth, that's (on average) 262500 satoshi's per person. Plenty enough to do business with.
If you divide 21 million bitcoin by 8 billion people, there's enough bitcoin for each person to have 262500 satoshi'.
But millioner/ billioner are accounlate 30% of total btc amount so what happen the price if whole of the world aware about btc?