Number Theory Challenge

12345678910111213
Across
  1. 1. : sixty-four thousand, three hundred eighty-eight
  2. 3. : seven million, one hundred seventy-eight thousand, eight hundred eighteen
  3. 6. : two hundred million, eight hundred thousand, seven hundred six
  4. 7. : two hundred million, seven hundred sixty-eight thousand, two hundred forty-two
  5. 11. : three hundred four thousand, five hundred seven
  6. 12. : one thousand, four hundred
  7. 13. : seventy-five thousand, twenty-four
Down
  1. 2. : eight hundred four thousand, seven hundred twenty-eight
  2. 4. : eight hundred seven thousand, two hundred eight
  3. 5. : eight hundred twenty-one million, four hundred forty-four
  4. 8. : seven million, eighty thousand, one hundred twenty-two
  5. 9. : two hundred million, four hundred sixty thousand
  6. 10. : two thousand, five hundred fifty-five