To find all the divisors of the number 133,840:
- 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 133,840:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
133,840 = 24 × 5 × 7 × 239
133,840 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 = (4 + 1) × (1 + 1) × (1 + 1) × (1 + 1) = 5 × 2 × 2 × 2 = 40
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 133,840
- 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
composite factor = 2
2 =
4
prime factor =
5
prime factor =
7
composite factor = 2
3 =
8
composite factor = 2 × 5 =
10
composite factor = 2 × 7 =
14
composite factor = 2
4 =
16
composite factor = 2
2 × 5 =
20
composite factor = 2
2 × 7 =
28
composite factor = 5 × 7 =
35
composite factor = 2
3 × 5 =
40
composite factor = 2
3 × 7 =
56
composite factor = 2 × 5 × 7 =
70
composite factor = 2
4 × 5 =
80
composite factor = 2
4 × 7 =
112
composite factor = 2
2 × 5 × 7 =
140
prime factor =
239
composite factor = 2
3 × 5 × 7 =
280
This list continues below...
... This list continues from above
composite factor = 2 × 239 =
478
composite factor = 2
4 × 5 × 7 =
560
composite factor = 2
2 × 239 =
956
composite factor = 5 × 239 =
1,195
composite factor = 7 × 239 =
1,673
composite factor = 2
3 × 239 =
1,912
composite factor = 2 × 5 × 239 =
2,390
composite factor = 2 × 7 × 239 =
3,346
composite factor = 2
4 × 239 =
3,824
composite factor = 2
2 × 5 × 239 =
4,780
composite factor = 2
2 × 7 × 239 =
6,692
composite factor = 5 × 7 × 239 =
8,365
composite factor = 2
3 × 5 × 239 =
9,560
composite factor = 2
3 × 7 × 239 =
13,384
composite factor = 2 × 5 × 7 × 239 =
16,730
composite factor = 2
4 × 5 × 239 =
19,120
composite factor = 2
4 × 7 × 239 =
26,768
composite factor = 2
2 × 5 × 7 × 239 =
33,460
composite factor = 2
3 × 5 × 7 × 239 =
66,920
composite factor = 2
4 × 5 × 7 × 239 =
133,840
40 factors (divisors)
What times what is 133,840?
What number multiplied by what number equals 133,840?
All the combinations of any two natural numbers whose product equals 133,840.
1 × 133,840 = 133,840
2 × 66,920 = 133,840
4 × 33,460 = 133,840
5 × 26,768 = 133,840
7 × 19,120 = 133,840
8 × 16,730 = 133,840
10 × 13,384 = 133,840
14 × 9,560 = 133,840
16 × 8,365 = 133,840
20 × 6,692 = 133,840
28 × 4,780 = 133,840
35 × 3,824 = 133,840
40 × 3,346 = 133,840
56 × 2,390 = 133,840
70 × 1,912 = 133,840
80 × 1,673 = 133,840
112 × 1,195 = 133,840
140 × 956 = 133,840
239 × 560 = 133,840
280 × 478 = 133,840
20 unique multiplications The final answer:
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