13 million looks like this 13,000,000 it is quite simple
Seven point thirteen billion is written as 7,130,000,000 in numbers. This representation includes seven billion and an additional one hundred thirty million. The commas separate the numbers into groups of three for easier reading.
13,012,008
1000000
3,000,000.
93,000,000
1,200,000
1,000,000
10,600,000
10,000,000
1,820,000
5,000,000
250,000