ACT Math : How to factor a number
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Example Questions
Example Question #1 : Other Factors / Multiples
The number 9 is the second smallest integer with 3 factors, 1, 3, and 9. What is the sum of the factors of the smallest integer with only 3 factors?
Here we must do two things. First we must find the smallest integer with 3 factors, then we must add those factors so that we can obtain our answer.
Looking at numbers less than 9 with only 3 factors, the only possibility is the number 4, whose factors are 1, 2, and 4.
The sum of these factors is 1 + 2 + 4 = 7
Example Question #1 : Other Factors / Multiples
If a and b are both factors of 64, which of the following could be a * b?
34
1920
200
128
128
The factors of 64 are: 1,2,4,8,16,32,64. Therefore, 128 could be the product of 16 and 8.
Example Question #1 : How To Factor A Number
Which of the following is not a factor of 52?
Listing all the factors of 52: 1,2,4,13,26,52.
3 is not one of the factors.
Example Question #591 : Arithmetic
Which of the following lists all the factors of 36?
36, 72
1, 36
2, 3
1, 2, 3, 4, 6, 9, 12, 18, 36
2, 4, 12, 18, 36
1, 2, 3, 4, 6, 9, 12, 18, 36
1, 2, 3, 4, 6, 9, 12, 18, 36 are all of the factors of 36.
Example Question #3 : Other Factors / Multiples
What are the factors of the number 12?
2, 6
3, 4
1, 12
1, 2, 3, 4, 6, 12
2, 3, 6
1, 2, 3, 4, 6, 12
The factors of a number are all the numbers that can be multiplied by an integer to get that number.
Example Question #592 : Arithmetic
What is the sum of the greatest common factor (GCF) and the least common multiple (LCM) of 
Prime factorize all numbers:
Therefore, 
Example Question #7 : How To Factor A Number
What is the power of the greatest prime factor of 
4
To get the answer to this question, just carefully prime factor the value 
First,
Now, 
For 
Now, this is a bit trickier for 
Thus, your total answer is:
Example Question #21 : Factors / Multiples
How many factors are there for the number 
To find the number of factors of a given number, the easiest thing to do is to make a table of the factors, starting with 
At this point, things begin to repeat. Thus, the total number of factors is 
Example Question #1662 : Act Math
What is the median value of the factors of 
There is no median.
To find the number of factors of a given number, the easiest thing to do is to make a table of the factors, starting with 
At this point, the values begin to repeat. This means that there are an even number of factors. At the "middle" of the list, we find 
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