0 - zero

11  - eleven

12  - twelve

15  - fifteen 

20  - twenty

33  - thirty-three

49  - forty-nine

50  - fifty

100  - a/one hundred

660  - six hundred and sixty

2,000  - two thousand 

14,000  - fourteen thousand

71,294  - seventy-one thousand, two hundred and ninety-four

1,000,000  - a/one million

5,000,000,000  - five billion