16
99,001
The original number would be 28. Swapped around, the number's digits are 82. The difference between the two numbers is 54.
If a number An consisting of n consecutive digits in ascending order is subtracted from the number An' obtained by reversing the digits of An, then the difference is always a constant. This constant is termed as the 'Unique number' Un as reported by me earlier in. For example, a 3-digit number 345 if subtracted from its reverse 543, yields a difference of 198. Thus U3 = 198. Another 3-digit number, say, 678 if subtracted from its reverse 876 will also yield the same difference, that is, 198. Thus for any number consisting of 3 consecutive digits, the Unique number U3 is always 198. Similarly for a number consisting of 4 consecutive digits, the Unique number U4 = 3087.
A number divisible by 123456789 must be 0 or bigger than 123456789. It must, therefore have 1 digit or 9 digits (or more). A remainder of 1 makes no difference to the number of digits. In any case, there can be no number of 4 digits that is divisible by 123456789.
28
28
899
No
16
If the number with the digits reversed can have a leading 0 so that it is a 1-digit number, then 16. Otherwise 13.
37
you are the number 48
99,001
The original number would be 28. Swapped around, the number's digits are 82. The difference between the two numbers is 54.
A digit is part of a number. the number 23 has two digits 2 and 3.