Factors of 13
The factors of 13 are 1, 13. 13 is a prime number: its only factors are 1 and itself. Prime factorisation: 13.
All 2 factors of 13
1, 13
A factor divides 13 exactly, with no remainder. Every factor has a partner: the pairs below multiply to 13. The negative factors are -1, -13, because a negative times a negative is positive.
Factor pairs of 13
| Pair | Product |
|---|---|
| 1 × 13 | 13 |
Stop at the square root (3): every pair after that is one you already have, the other way round.
Prime factorisation of 13: 13
| Divide | by the smallest prime | Result |
|---|---|---|
| 13 | 13 | 1 |
So 13 = 13.
The number of factors comes from the exponents: (1 + 1) = 2.
How to find the factors of 13
- Start with 1 and 13: every number has those two.
- Test 2, 3, 4, … up to the square root of 13, which is about 3.
- Each time a number divides exactly, write it down with its partner (the quotient).
- Use the divisibility rules to skip work: by 2 no (the last digit is odd); by 3 no (the digit sum is 4); by 5 no (the last digit is 3).
- Put the list in order: 1, 13.
🧮 Calculator
The answer appears here, with the working in words.
✏️ Five questions, answers hidden
1. List the factors of 14.
Answer: 1, 2, 7, 14
2. Write the prime factorisation of 26.
Answer: 2 × 13
3. How many factors does 13 have?
Answer: 2
4. What is the largest factor of 13 other than itself?
Answer: 1
5. Is 15 prime or composite?
Answer: composite
📚 The class this belongs to
Factors are taught in Grade 4 and 5 in the US, Year 5 and 6 in the UK, Class 4 to 6 in CBSE (NCERT Class 6, Playing with Numbers) and Year 5 and 6 in Australia.
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