4 billion.
590909090909.09
Sixteen point two billion is how I would write it.
66%
66.67%
2/3
2.666 recurring
670,000
4 --- 6
Two thirds as a decimal is 0.6666666 \9the digit 6 repeats to infinity).
2/3 as a percentage of 1 billion = 2/3 * 100/1000000000 = 0.00000006666667
3/3 of a billion = billion