Factors of 36
The factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, 36. No, 36 is a composite number. Its prime factorization is 2^2 × 3^2.
Factor pairs of 36
Every factor has a partner that multiplies with it to give 36. 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 (here at 6 × 6), you have them all.
| Pair | Check |
|---|---|
| 1 and 36 | 1 × 36 = 36 |
| 2 and 18 | 2 × 18 = 36 |
| 3 and 12 | 3 × 12 = 36 |
| 4 and 9 | 4 × 9 = 36 |
| 6 and 6 | 6 × 6 = 36 |
Prime factorization of 36, step by step
Divide by the smallest prime that goes in evenly, then repeat on the result until you reach 1. The divisors you used are the prime factors.
| Step | Divide | Result |
|---|---|---|
| 1 | 36 ÷ 2 | 18 |
| 2 | 18 ÷ 2 | 9 |
| 3 | 9 ÷ 3 | 3 |
| 4 | 3 ÷ 3 | 1 |
So 36 = 2 × 2 × 3 × 3, written compactly as 2^2 × 3^2.
Divisibility checks for 36
The quick rules a student uses before dividing, applied to 36:
| Divisible by | Rule | For 36 | Result |
|---|---|---|---|
| 2 | last digit is even | last digit 6 | yes |
| 3 | digit sum divisible by 3 | digits add to 9 | yes |
| 4 | last two digits divisible by 4 | 36 ÷ 4 | yes |
| 5 | last digit is 0 or 5 | last digit 6 | no |
| 6 | divisible by both 2 and 3 | even, digit sum 9 | yes |
| 8 | last three digits divisible by 8 | 36 ÷ 8 | no |
| 9 | digit sum divisible by 9 | digits add to 9 | yes |
| 10 | last digit is 0 | last digit 6 | no |
Frequently Asked Questions
What are the factors of 36?
The factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, 36.
Is 36 a prime number?
No, 36 is a composite number. Its prime factorization is 2^2 × 3^2.
How many factors does 36 have?
36 has 9 factors. You can get that count from the prime factorization without listing them: add 1 to each exponent in 2^2 × 3^2 and multiply -- (2+1) × (2+1) = 9.
Is 36 even or odd, and is it a perfect square?
36 is even (2 is one of its factors), and it is a perfect square: 6 × 6 = 36, which is why its factor list has an odd number of entries.
What is the sum of the factors of 36?
1 + 2 + 3 + 4 + 6 + 9 + 12 + 18 + 36 = 91. Leaving out 36 itself, the proper factors add to 55, more than 36, so 36 is an abundant number.
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