In exponential notation (or scientific notation):
10^9 (where ^ means exponentiation)
or 1x10^9
You could also write 1E9 or 1E+9
Note in the U.K. billion means 10^12, referring to 10^9 instead as "milliard."
One billion.
Ways to write one billion is: one billion,1 billion,1,000,000,000,you can write it in roman numeral several different ways,with tally marks, etc.
One quintillion.
1.billion
To write one billion three million, you would write out the number 1,003,000,000.
As a number it is: 1,800,000,000 = 1.8 billion
As a number: 1,000,000,000 = one billion
10,000,000=107
1,000,000,001
one billion
1 and one half billion can be written as 1.5 billion.
One billion numerically is: 1,000,000,000