1. Prime Factorization Tricks!

2. 1
ALL NUMBERS HAVE 1 AS A FACTOR!

3. 2 Even numbers! Numbers ending in 0, 2, 4, 6, 8 Example: 1092843972
2 is a factor!

4. 3 When you add up the digits, the number is divisible by 3 Example:
489
4+8+9=21
21/3=7
Therefore 3 is a factor of 489

5. 4 If the last 2 digits are divisible by 4, then the whole number is!
Example:
344
_44/4 =11
344 has 4 as a factor!

6. 5 Always ends in 0 or 5 Example: 928420 _____0
This number has 5 as a factor!

7. 6
If you already know the number has the factors 3 and 2, then it also has 6!
Example:
336
__6= even number; 2 is a factor!
3+3+6=12 12/3=4; 3 is a factor!
If 2 and 3 are factors, 6 is a factor!

8. 7
No special rule for 7s 
I guess you guys will just have to study them harder…

9. 8 If the last 3 numbers are divisible by 8, then 8 is a factor!
Example:
7168
_168/8=_21
This has a factor of 8!

10. 9 When you add up the digits, the number is divisible by 9! Example:
288
2+8+8=18
18/9=2
This number has a factor of 9!

11. 10 Number that end in 0! Example: 29832740 _______0
This number has a factor of 10!

12. I HOPE THIS HELPS!