5,000,000,000
1,000,000,000 = 1 billion.
2.3 billion is written: 2,300,000,000
The number 1 billion can be written as the Roman numeral [M] with a horizontal bar above it (which I can't write with my keyboard).
2000000000
iiimcimcicvicmvicmivciiicvmcivivivmcmmicvivicmvmciviciciiiiicmvmvmmmmmmicimvcimvicivivvivicmvcivicmviicicicmmcicmvmvmcccimvicmciicimvmmvcicimmmm
5.9 billion = 5,900,000,000
1,000,000,000 = 1 billion.
2.3 billion is written: 2,300,000,000
The number 1 billion can be written as the Roman numeral [M] with a horizontal bar above it (which I can't write with my keyboard).
2000000000
iiimcimcicvicmvicmivciiicvmcivivivmcmmicvivicmvmciviciciiiiicmvmvmmmmmmicimvcimvicivivvivicmvcivicmviicicicmmcicmvmvmcccimvicmciicimvmmvcicimmmm
7,000,000,000
90,000,000,000
1,200,000,000
7,750.000,000
8,000,000,000
18,400,000,000