NUMBERS!

12345678910111213141516171819
Across
  1. 2. neither prime nor composite
  2. 4. smallest number with 4 factors
  3. 8. fingers of one hand
  4. 10. smallest "teen" number
  5. 11. smallest two-digit number
  6. 13. 3+(3X3)+3+3
  7. 15. largest "teen" number
  8. 16. most likely the sum of two fair dice
  9. 18. smallest odd two-digit number
  10. 19. even prime
Down
  1. 1. sum of all single-digit squares
  2. 3. smallest even cube
  3. 4. smallest 3-syllable number
  4. 5. smallest even square
  5. 6. smallest odd prime
  6. 7. 2 multiplied by itself 4 times
  7. 9. sum of all single-digit cubes
  8. 11. smallest number with 6 factors
  9. 12. 1+2+3+4+5
  10. 14. fingers+toes
  11. 17. emptiness