What are the common factors (divisors) of the numbers 420,300 and 980,700?
The common factors of the numbers 420,300 and 980,700 are all the factors of their 'greatest common factor', gcf
Calculate the greatest (highest) common factor (divisor).
Follow the two steps below.
1. Perform the prime factorization of the two numbers:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
420,300 = 22 × 32 × 52 × 467
420,300 is not a prime number but a composite one.
980,700 = 22 × 3 × 52 × 7 × 467
980,700 is not a prime number but a composite one.
- Prime number: a natural number that is divisible only by 1 and itself. A prime number has exactly two factors: 1 and itself.
- Examples of prime numbers: 2 (factors 1, 2), 3 (factors 1, 3), 5 (factors 1, 5), 7 (factors 1, 7), 11 (factors 1, 11), 13 (factors 1, 13), ...
- A composite number is a natural number that has at least one factor other than 1 and itself. So it is neither a prime number nor 1.
- Examples of composite numbers: 4 (it has 3 factors: 1, 2, 4), 6 (it has 4 factors: 1, 2, 3, 6), 8 (it has 4 factors: 1, 2, 4, 8), 9 (it has 3 factors: 1, 3, 9), 10 (it has 4 factors: 1, 2, 5, 10), 12 (it has 6 factors: 1, 2, 3, 4, 6, 12), ...
2. Calculate the greatest (highest) common factor (divisor), gcf, hcf, gcd:
Multiply all the common prime factors, taken by their smallest exponents (the smallest powers).
gcf, hcf, gcd (420,300; 980,700) = 22 × 3 × 52 × 467 = 140,100
How to count the number of factors of a number?
Without actually finding the factors
- If a number N is prime factorized as:
N = am × bk × cz
where a, b, c are the prime factors and m, k, z are their exponents, natural numbers, .... - ...
- Then the number of factors of the number N can be calculated as:
n = (m + 1) × (k + 1) × (z + 1) - ...
- In our case, the number of factors is calculated as:
- n = (2 + 1) × (1 + 1) × (2 + 1) × (1 + 1) = 3 × 2 × 3 × 2 = 36
But to actually calculate the factors, see below...
3. Multiply the prime factors of the 'gcf':
- Multiply the prime factors involved in the prime factorization of the GCF in all their unique combinations, that give different results.
- Also consider the exponents of the prime factors (example: 32 = 3 × 3 = 9).
- Also add 1 to the list of factors (divisors). All the numbers are divisible by 1.
All the factors (divisors) are listed below - in ascending order
The list of factors (divisors):
Numbers other than 1 that are not prime factors are composite instead.
neither prime nor composite =
1
prime factor =
2
prime factor =
3
composite factor = 2
2 =
4
prime factor =
5
composite factor = 2 × 3 =
6
composite factor = 2 × 5 =
10
composite factor = 2
2 × 3 =
12
composite factor = 3 × 5 =
15
composite factor = 2
2 × 5 =
20
composite factor = 5
2 =
25
composite factor = 2 × 3 × 5 =
30
composite factor = 2 × 5
2 =
50
composite factor = 2
2 × 3 × 5 =
60
composite factor = 3 × 5
2 =
75
composite factor = 2
2 × 5
2 =
100
composite factor = 2 × 3 × 5
2 =
150
composite factor = 2
2 × 3 × 5
2 =
300
This list continues below...
... This list continues from above
prime factor =
467
composite factor = 2 × 467 =
934
composite factor = 3 × 467 =
1,401
composite factor = 2
2 × 467 =
1,868
composite factor = 5 × 467 =
2,335
composite factor = 2 × 3 × 467 =
2,802
composite factor = 2 × 5 × 467 =
4,670
composite factor = 2
2 × 3 × 467 =
5,604
composite factor = 3 × 5 × 467 =
7,005
composite factor = 2
2 × 5 × 467 =
9,340
composite factor = 5
2 × 467 =
11,675
composite factor = 2 × 3 × 5 × 467 =
14,010
composite factor = 2 × 5
2 × 467 =
23,350
composite factor = 2
2 × 3 × 5 × 467 =
28,020
composite factor = 3 × 5
2 × 467 =
35,025
composite factor = 2
2 × 5
2 × 467 =
46,700
composite factor = 2 × 3 × 5
2 × 467 =
70,050
composite factor = 2
2 × 3 × 5
2 × 467 =
140,100
36 common factors (divisors)
What times what is 140,100?
What number multiplied by what number equals 140,100?
All the combinations of any two natural numbers whose product equals 140,100.
1 × 140,100 = 140,100
2 × 70,050 = 140,100
3 × 46,700 = 140,100
4 × 35,025 = 140,100
5 × 28,020 = 140,100
6 × 23,350 = 140,100
10 × 14,010 = 140,100
12 × 11,675 = 140,100
15 × 9,340 = 140,100
20 × 7,005 = 140,100
25 × 5,604 = 140,100
30 × 4,670 = 140,100
50 × 2,802 = 140,100
60 × 2,335 = 140,100
75 × 1,868 = 140,100
100 × 1,401 = 140,100
150 × 934 = 140,100
300 × 467 = 140,100
18 unique multiplications