1,274,915,000. A trick is that you place a comma whenever there's a billion, million, thousand, hundred, etc. in your sentence. So you would write it as 1 (comma) 274 (comma) 915 (comma) 000. You need the zeros at the end because a billion always has nine places after the first comma. Since there were only six, that means the rest has to be zeros.
1,274,915
1,274,915,000.
1,274,915,000
Expressed in figures, this is equal to 15,000,303,048.
18000003002615?
15,000,000,400,000
Fifteen thousand five hundred
3 billion six hundred one thousand fifteen = 3,000,601,0153,000,601,015 in standard form is written 3.000601015 x 109
1,274,915,000
1,274,915,000
15,000,400,000
The standard form for thirty million two thousand fifteen (30,002,015) is 3.0002015 × 107
The standard digit form is 67,400,015,302
80,495,077,415
15000
The standard form is 11,015
Five thousand six hundred fifteen ten-thousandths in standard form is 0.5615
Seventeen billion since there is no such number as fifiteen! But if you meant fifteen thousand billion, then that is bigger.
Depends on the convention where you are. In the USA its fifteen billion but in the UK and some other places fifteen billion is 1,000 times larger. Fifteen thousand million should be clear in any case.