To find all the divisors of the number 168,420:
- 1. Decompose the number into prime factors.
- See how you can find out how many factors (divisors) the number has, without actually calculating them.
- 2. Multiply the prime factors in all their unique combinations, that yield different results.
1. Carry out the prime factorization of the number 168,420:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
168,420 = 22 × 3 × 5 × 7 × 401
168,420 is not a prime number but a composite one.
- Prime number: a natural number that is divisible (divided evenly) only by 1 and itself. A prime number has exactly two factors: 1 and the number 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), ...
- Composite number: 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), ...
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) × (1 + 1) × (1 + 1) × (1 + 1) = 3 × 2 × 2 × 2 × 2 = 48
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 168,420
- Multiply the prime factors involved in the prime factorization of the number in all their unique combinations, that give different results.
- Also consider the exponents of these prime factors.
- 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 factors (divisors).
neither prime nor composite =
1
prime factor =
2
prime factor =
3
composite factor = 2
2 =
4
prime factor =
5
composite factor = 2 × 3 =
6
prime factor =
7
composite factor = 2 × 5 =
10
composite factor = 2
2 × 3 =
12
composite factor = 2 × 7 =
14
composite factor = 3 × 5 =
15
composite factor = 2
2 × 5 =
20
composite factor = 3 × 7 =
21
composite factor = 2
2 × 7 =
28
composite factor = 2 × 3 × 5 =
30
composite factor = 5 × 7 =
35
composite factor = 2 × 3 × 7 =
42
composite factor = 2
2 × 3 × 5 =
60
composite factor = 2 × 5 × 7 =
70
composite factor = 2
2 × 3 × 7 =
84
composite factor = 3 × 5 × 7 =
105
composite factor = 2
2 × 5 × 7 =
140
composite factor = 2 × 3 × 5 × 7 =
210
prime factor =
401
This list continues below...
... This list continues from above
composite factor = 2
2 × 3 × 5 × 7 =
420
composite factor = 2 × 401 =
802
composite factor = 3 × 401 =
1,203
composite factor = 2
2 × 401 =
1,604
composite factor = 5 × 401 =
2,005
composite factor = 2 × 3 × 401 =
2,406
composite factor = 7 × 401 =
2,807
composite factor = 2 × 5 × 401 =
4,010
composite factor = 2
2 × 3 × 401 =
4,812
composite factor = 2 × 7 × 401 =
5,614
composite factor = 3 × 5 × 401 =
6,015
composite factor = 2
2 × 5 × 401 =
8,020
composite factor = 3 × 7 × 401 =
8,421
composite factor = 2
2 × 7 × 401 =
11,228
composite factor = 2 × 3 × 5 × 401 =
12,030
composite factor = 5 × 7 × 401 =
14,035
composite factor = 2 × 3 × 7 × 401 =
16,842
composite factor = 2
2 × 3 × 5 × 401 =
24,060
composite factor = 2 × 5 × 7 × 401 =
28,070
composite factor = 2
2 × 3 × 7 × 401 =
33,684
composite factor = 3 × 5 × 7 × 401 =
42,105
composite factor = 2
2 × 5 × 7 × 401 =
56,140
composite factor = 2 × 3 × 5 × 7 × 401 =
84,210
composite factor = 2
2 × 3 × 5 × 7 × 401 =
168,420
48 factors (divisors)
What times what is 168,420?
What number multiplied by what number equals 168,420?
All the combinations of any two natural numbers whose product equals 168,420.
1 × 168,420 = 168,420
2 × 84,210 = 168,420
3 × 56,140 = 168,420
4 × 42,105 = 168,420
5 × 33,684 = 168,420
6 × 28,070 = 168,420
7 × 24,060 = 168,420
10 × 16,842 = 168,420
12 × 14,035 = 168,420
14 × 12,030 = 168,420
15 × 11,228 = 168,420
20 × 8,421 = 168,420
21 × 8,020 = 168,420
28 × 6,015 = 168,420
30 × 5,614 = 168,420
35 × 4,812 = 168,420
42 × 4,010 = 168,420
60 × 2,807 = 168,420
70 × 2,406 = 168,420
84 × 2,005 = 168,420
105 × 1,604 = 168,420
140 × 1,203 = 168,420
210 × 802 = 168,420
401 × 420 = 168,420
24 unique multiplications The final answer:
(scroll down)