It is 1 280 000 000.
280,000,000,000 or 280 billion
Yes, it is 280 times as big.
280 = CCLXXX
280 × 10^8
I write 620 billion as 620 billion.
Sixteen point two billion is how I would write it.
2800000000 Million dollars
It is: 2.8*10^11 = 280,000,000,000
$2.80
3.5
You write 3.56 billion as 3,560,000,000.