When the first digit is 1, there are only 3 choices for the 2nd digit: 0, 2, 4
When the 2nd digit is 0, there are 10 choices for the 3rd digit and only 8 choices for the 4th digit:2, 3, 4, 5, 6, 7, 8, 9. So: 10 x 8 ==80
When the 2nd digit is 2, there are 10 choices for the 3rd digit and only 6 choices for the 4th digit: 4, 5, 6, 7, 8, 9. So:10 x 6 ==60
When the 2nd digit is 4, there are 10 choices for the 3rd digit and only 2 choices for the 4th digit: 8 and 9. So: 10 x 2 ==20
Therefore beginning with 1 as the 1st digit from the left, we have a total of: 80 + 60 + 20 =160 such integers.
This pattern is repeated for every 1st digit from 1 to 9. Therefore, there are a total of: 9 x 160 =1,440 such 4-digit integers.
Note: I wrote a short computer code in C++ and confirms the above total of 1440 integers. If needed, it can be printed.