The first digit can be any one of the numbers 2-9 That a total of 8 numbers.
The next 6 digits can be any permutation of 6 from the numbers 0 to 9.
(10 numbers)
nPr = n! / r!
so here we have 10P6 = 10! / 6! = 10*9*8*7 = 5040
So final answer is 8 * 5040 = 40,320