Factors of 13
The factors of 13 are 1, 13. Yes, 13 is a prime number. Its only factors are 1 and 13.
Factor pairs of 13
Every factor has a partner that multiplies with it to give 13. Listing pairs from the outside in is the fastest way to find all the factors: once the two numbers in a pair meet in the middle, you have them all.
| Pair | Check |
|---|---|
| 1 and 13 | 1 × 13 = 13 |
Prime factorization of 13, step by step
13 is prime, so the ladder is one rung: nothing smaller than 13 divides it except 1. To confirm, you only need to test primes up to √13 ≈ 3: 13 ÷ 2 leaves 1; 13 ÷ 3 leaves 1.
Divisibility checks for 13
The quick rules a student uses before dividing, applied to 13:
| Divisible by | Rule | For 13 | Result |
|---|---|---|---|
| 2 | last digit is even | last digit 3 | no |
| 3 | digit sum divisible by 3 | digits add to 4 | no |
| 4 | last two digits divisible by 4 | 13 ÷ 4 | no |
| 5 | last digit is 0 or 5 | last digit 3 | no |
| 6 | divisible by both 2 and 3 | odd, digit sum 4 | no |
| 8 | last three digits divisible by 8 | 13 ÷ 8 | no |
| 9 | digit sum divisible by 9 | digits add to 4 | no |
| 10 | last digit is 0 | last digit 3 | no |
Frequently Asked Questions
What are the factors of 13?
The factors of 13 are 1, 13.
Is 13 a prime number?
Yes, 13 is a prime number. Its only factors are 1 and 13.
How many factors does 13 have?
13 has 2 factors.
Is 13 even or odd?
13 is odd (2 is not a factor).
What is the sum of the factors of 13?
1 + 13 = 14. Leaving out 13 itself, the proper factors add to 1, less than 13, so 13 is a deficient number.
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