The Billion Dollar Ransom has 189 pages.
I write 620 billion as 620 billion.
CLXXXIX
Sixteen point two billion is how I would write it.
5,602,347,189 = five billion, six hundred two million, three hundred forty-seven thousand, one hundred eighty-nine.
You write 3.56 billion as 3,560,000,000.
189 = CLXXXIX
40,300,000,000
As a number it is: 1,800,000,000 = 1.8 billion
Since you asked how I would write the number, the answer is 1031.
1,000 billion billion is: 1,000,000,000,000,000,000,000
35.9204067 billion