The common abbreviation for a billion dollars is $1B. To express the magnitude of a billion dollars in its extended form, the notation $1,000,000,000 is used.
Definition: “a cardinal number represented in the United States by 1 followed by 9 zeroes, and in Great Britain by 1 followed by 12 zeroes” Since the value of one billion is different in the United States and the United Kingdom, the dollar quantity one billion is abbreviated as $1B more frequently in the United States.
Both $1BN and $1bill are common shorthand references to 1 billion dollars. One billion dollars and one billon dollars are both acceptable alternatives.