What are the characteristics of numbers divisible by 11?

What are the characteristics of numbers divisible by 11?

The characteristic of a number divisible by 11 is to add the odd digit and even digit of a number from right to left, and then calculate their difference. If the difference is a multiple of 11 (including 0), then the original number must be divisible by 11. For example, judge whether 491678 can be divisible by 11