Question 578164

With six digits, and the order is important (permutations) there could be many thousands of options.

where was the 581? the first 3 digits? the last 3?  

Assuming the first 3 digits are 581 and 0 is allowed:

5 8 1 _ _ _

5 8 1 * 10 * 10 * 10, so there could be 10^3 = 1000 possible cominations

If you don't know where the 581 is in the sequence it could be 

_ 5 8 1 _ _ 

_ _ 5 8 1 _

_ _ _ 581

giving rise to 3 other sets of 1000, so 4 x 1000 = 4000 combinations in total