Characteristics of numbers divisible by 7.11.13.9

Characteristics of numbers divisible by 7.11.13.9

The characteristics of numbers divisible by 9 are as follows
If the sum of the numbers on each bit of a number can be divided by 9, then the number can be divided by 9
Characteristics of numbers divisible by 11
If the difference between the sum of odd and even digits of an integer can be divided by 11, then the number can be divided by 11
Characteristics of numbers divisible by 7 and 13
If the difference between the last three digits of an integer and the number before the last three digits can be divided by 7 or 13, then the number can be divided by 7 or 13
In the fifth grade of primary school (Mathematical Olympiad), there are