Write the greatest 7 digit number using the digits 0,1 ,4 ,5 ,2 only once

Dear student,
since 5 digits are provided, then to find the greatest 7  digit number, we will use two 9s at the begining. 
the greatest 7 digit number using the digits 0,1 ,4 ,5 ,2 only once will be

9954210

Regards