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| − | In [[integer]] arithmetic, a '''factor''' is an integer that evenly divides another integer. For example, 3 is a factor of 24 because 24 divided by 3 does not leave a remainder. 5 is not a factor of 24.
| + | A '''factor''' is an [[integer]] that evenly divides another integer. For example, 3 is a factor of 24 because 24 divided by 3 does not leave a remainder. 5 is not a factor of 24. |
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| | Factors are sometimes called '''divisors''' to distinguish them from '''prime factors'''. A prime factor is a divisor that is a [[Prime Number|prime number]]. 2 and 3 are prime factors of 24. 6 is not a prime factor because it is a [[composite number]]. | | Factors are sometimes called '''divisors''' to distinguish them from '''prime factors'''. A prime factor is a divisor that is a [[Prime Number|prime number]]. 2 and 3 are prime factors of 24. 6 is not a prime factor because it is a [[composite number]]. |
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| | Every integer has a one unique prime factorization, though it may have multiple non-prime factorizations (e.g. 24 = 2 * 12, 24 = 3 * 8). | | Every integer has a one unique prime factorization, though it may have multiple non-prime factorizations (e.g. 24 = 2 * 12, 24 = 3 * 8). |
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| − | The number of divisors of an integer may be determined from its prime factorization when expressed in exponent form, by incrementing each exponent by 1 and multiplying the results. In the example above, the exponts of 2 and 3 are 3 and 1, respectively. The number of divisors of 24 is therefore | + | The number of divisors of an integer may be determined from its prime factorization when expressed in exponent form, by incrementing each exponent by 1 and multiplying the results. In the example above, the exponents of prime factors 2 and 3 are 3 and 1, respectively. The number of divisors of 24 is therefore |
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| | :(3 + 1) * (1 + 1) = 8 | | :(3 + 1) * (1 + 1) = 8 |
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| | and they are 1, 2, 3, 4, 6, 8, 12, and 24. | | and they are 1, 2, 3, 4, 6, 8, 12, and 24. |