An American “billion” is 1,000,000,000 which is a thousand million.
A British “billion” is 1,000,000,000,000 which is a million million.
In scientific notation, a billion is written as 10^9.
A billion is sometimes referred to as a milliard, although this terminology is archaic British English and rarely used in modern English.
About a billion minutes ago, the Roman Empire was flourishing and Christianity was emerging.