What is the greatest 7 digit number without repeating any digit?

I am number greater than 70 000 but less than 90 000.My ones digit is the only even prime number.My tens digit id the same as my ones digit.My ten thousands digit is four times my ones digits.Both my hundreds and thousands digits are half the ten thousands digits.What number am i?

how about

9876543 ?

part b:

xxxxx
ones is even prime: 2
xxxx2
tens=ones = 2
xxx22
10K = 4*ones = 8
8xx22
100,1K = 8/2 = 4
84422

To find the greatest 7-digit number without repeating any digit, we can start by listing all the digits from 9 to 1 in descending order. Then, we can fill in the remaining digits in ascending order, starting from 0. Here is how you can do it step by step:

1. The first digit can be any digit from 9 to 1 since we want the greatest number, so let's choose 9.
2. The second digit can be any digit from 8 to 0, excluding the digit 9 which has already been used. Let's choose 8.
3. The third digit can be any digit from 7 to 0, excluding the digits 9 and 8 which have already been used. Let's choose 7.
4. The fourth digit can be any digit from 6 to 0, excluding the digits 9, 8, and 7 which have already been used. Let's choose 6.
5. The fifth digit can be any digit from 5 to 0, excluding the digits 9, 8, 7, and 6 which have already been used. Let's choose 5.
6. The sixth digit can be any digit from 4 to 0, excluding the digits 9, 8, 7, 6, and 5 which have already been used. Let's choose 4.
7. The seventh digit can be any digit from 3 to 0, excluding the digits 9, 8, 7, 6, 5, and 4 which have already been used. Let's choose 3.

As a result, the greatest 7-digit number without repeating any digit is 9876543.