15,000,000,000,000.
One billion is 1 with 9 zeroes or 1,000,000,000.So 15000 billion is 15,000,000,000,000 or simply 15 trillion.
1476 billion is 1,476,000,000,000
It is: 124,000,000,000 = 124 billion
15000 (all integers are rational numbers).
1.48 billion = 1,480,000,000
3,200,000,000