Math Puzzle Number 1

I promise a Math Circle coffee cup to the first person who answers this question. You can post your answer on the blog.

Problem 1 for Math Teachers’ Circle:

Given that 40! = abc def 283 247 897 734 345 611 269 596 115 894 272 pqr stu vwx

Find p;q; r; s; t;u;v;w;x, i.e. the last nine digits of the number. Be sure to explain how your answer was determined without the aid of a calculator.

Extra just for fun: Find a;b;c;d;e; f , i.e. the first six digits