Factors of 7
The factors of 7 are 1, 7. Yes, 7 is a prime number. Its only factors are 1 and 7.
Factors of 7
1, 7
2 factors
Prime or Composite
Prime
Perfect Square
No
Prime Factorization
7
Sum of Factors
8 (1 without 7 itself)
Factor pairs of 7
Every factor has a partner that multiplies with it to give 7. 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 7 | 1 × 7 = 7 |
Prime factorization of 7, step by step
7 is prime, so the ladder is one rung: nothing smaller than 7 divides it except 1. To confirm, you only need to test primes up to √7 ≈ 2: 7 ÷ 2 leaves 1.
Divisibility checks for 7
The quick rules a student uses before dividing, applied to 7:
| Divisible by | Rule | For 7 | Result |
|---|---|---|---|
| 2 | last digit is even | last digit 7 | no |
| 3 | digit sum divisible by 3 | digits add to 7 | no |
| 4 | last two digits divisible by 4 | 7 ÷ 4 | no |
| 5 | last digit is 0 or 5 | last digit 7 | no |
| 6 | divisible by both 2 and 3 | odd, digit sum 7 | no |
| 8 | last three digits divisible by 8 | 7 ÷ 8 | no |
| 9 | digit sum divisible by 9 | digits add to 7 | no |
| 10 | last digit is 0 | last digit 7 | no |
Frequently Asked Questions
What are the factors of 7?
The factors of 7 are 1, 7.
Is 7 a prime number?
Yes, 7 is a prime number. Its only factors are 1 and 7.
How many factors does 7 have?
7 has 2 factors.
Is 7 even or odd?
7 is odd (2 is not a factor).
What is the sum of the factors of 7?
1 + 7 = 8. Leaving out 7 itself, the proper factors add to 1, less than 7, so 7 is a deficient number.
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