Round the number into the nearest thousand makes it 8000, so the first number is 7, and it ha 4 digits. Since it is said that if you read the number forward or backward it is still the same, therefore, the 1st and 4th numbers are the same and the 2nd and 3rd numbers are also the same. So, the 4th number is 7. We now use: 7 + x + x + 7 = 24, x is the 2nd and 3rd numbers, which are the same. We have: 2x + 14 = 24 --> 2x = 10 --> x = 5. The number is 7557.