The way that you wrote it in your question is just fine.
13.7 billion
137!
137 is in decimal form.
137 million in dollars is $137,000,000
137/200 = 0.685
I write 620 billion as 620 billion.
137 written in Roman numerals is CXXXVII
Sixteen point two billion is how I would write it.
Well, sweetheart, to write 137 percent as a fraction, you simply take 137 and put it over 100 because percent means "per 100." So, 137 percent as a fraction is 137/100. It's as easy as pie, darling!
The Colbert Report - 2005 Jonathan Alter 4-137 was released on: USA: 23 October 2008
The Colbert Report - 2005 Penn Jillette 2-137 was released on: USA: 1 November 2006
The Colbert Report - 2005 Lawrence Wilkerson 3-137 was released on: USA: 31 October 2007
The Colbert Report - 2005 Colum McCann 9-137 was released on: USA: 8 August 2013