Factors of 43
The factors of 43 are 1, 43. Yes, 43 is a prime number. Its only factors are 1 and 43.
Factor pairs of 43
Every factor has a partner that multiplies with it to give 43. 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 43 | 1 × 43 = 43 |
Prime factorization of 43, step by step
43 is prime, so the ladder is one rung: nothing smaller than 43 divides it except 1. To confirm, you only need to test primes up to √43 ≈ 6: 43 ÷ 2 leaves 1; 43 ÷ 3 leaves 1; 43 ÷ 5 leaves 3.
Divisibility checks for 43
The quick rules a student uses before dividing, applied to 43:
| Divisible by | Rule | For 43 | Result |
|---|---|---|---|
| 2 | last digit is even | last digit 3 | no |
| 3 | digit sum divisible by 3 | digits add to 7 | no |
| 4 | last two digits divisible by 4 | 43 ÷ 4 | no |
| 5 | last digit is 0 or 5 | last digit 3 | no |
| 6 | divisible by both 2 and 3 | odd, digit sum 7 | no |
| 8 | last three digits divisible by 8 | 43 ÷ 8 | no |
| 9 | digit sum divisible by 9 | digits add to 7 | no |
| 10 | last digit is 0 | last digit 3 | no |
Frequently Asked Questions
What are the factors of 43?
The factors of 43 are 1, 43.
Is 43 a prime number?
Yes, 43 is a prime number. Its only factors are 1 and 43.
How many factors does 43 have?
43 has 2 factors.
Is 43 even or odd?
43 is odd (2 is not a factor).
What is the sum of the factors of 43?
1 + 43 = 44. Leaving out 43 itself, the proper factors add to 1, less than 43, so 43 is a deficient number.
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