To find all the divisors of the number 840,000:
- 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 840,000:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
840,000 = 26 × 3 × 54 × 7
840,000 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 = (6 + 1) × (1 + 1) × (4 + 1) × (1 + 1) = 7 × 2 × 5 × 2 = 140
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 840,000
- 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
3 =
8
composite factor = 2 × 5 =
10
composite factor = 2
2 × 3 =
12
composite factor = 2 × 7 =
14
composite factor = 3 × 5 =
15
composite factor = 2
4 =
16
composite factor = 2
2 × 5 =
20
composite factor = 3 × 7 =
21
composite factor = 2
3 × 3 =
24
composite factor = 5
2 =
25
composite factor = 2
2 × 7 =
28
composite factor = 2 × 3 × 5 =
30
composite factor = 2
5 =
32
composite factor = 5 × 7 =
35
composite factor = 2
3 × 5 =
40
composite factor = 2 × 3 × 7 =
42
composite factor = 2
4 × 3 =
48
composite factor = 2 × 5
2 =
50
composite factor = 2
3 × 7 =
56
composite factor = 2
2 × 3 × 5 =
60
composite factor = 2
6 =
64
composite factor = 2 × 5 × 7 =
70
composite factor = 3 × 5
2 =
75
composite factor = 2
4 × 5 =
80
composite factor = 2
2 × 3 × 7 =
84
composite factor = 2
5 × 3 =
96
composite factor = 2
2 × 5
2 =
100
composite factor = 3 × 5 × 7 =
105
composite factor = 2
4 × 7 =
112
composite factor = 2
3 × 3 × 5 =
120
composite factor = 5
3 =
125
composite factor = 2
2 × 5 × 7 =
140
composite factor = 2 × 3 × 5
2 =
150
composite factor = 2
5 × 5 =
160
composite factor = 2
3 × 3 × 7 =
168
composite factor = 5
2 × 7 =
175
composite factor = 2
6 × 3 =
192
composite factor = 2
3 × 5
2 =
200
composite factor = 2 × 3 × 5 × 7 =
210
composite factor = 2
5 × 7 =
224
composite factor = 2
4 × 3 × 5 =
240
composite factor = 2 × 5
3 =
250
composite factor = 2
3 × 5 × 7 =
280
composite factor = 2
2 × 3 × 5
2 =
300
composite factor = 2
6 × 5 =
320
composite factor = 2
4 × 3 × 7 =
336
composite factor = 2 × 5
2 × 7 =
350
composite factor = 3 × 5
3 =
375
composite factor = 2
4 × 5
2 =
400
composite factor = 2
2 × 3 × 5 × 7 =
420
composite factor = 2
6 × 7 =
448
composite factor = 2
5 × 3 × 5 =
480
composite factor = 2
2 × 5
3 =
500
composite factor = 3 × 5
2 × 7 =
525
composite factor = 2
4 × 5 × 7 =
560
composite factor = 2
3 × 3 × 5
2 =
600
composite factor = 5
4 =
625
composite factor = 2
5 × 3 × 7 =
672
composite factor = 2
2 × 5
2 × 7 =
700
composite factor = 2 × 3 × 5
3 =
750
composite factor = 2
5 × 5
2 =
800
composite factor = 2
3 × 3 × 5 × 7 =
840
composite factor = 5
3 × 7 =
875
This list continues below...
... This list continues from above
composite factor = 2
6 × 3 × 5 =
960
composite factor = 2
3 × 5
3 =
1,000
composite factor = 2 × 3 × 5
2 × 7 =
1,050
composite factor = 2
5 × 5 × 7 =
1,120
composite factor = 2
4 × 3 × 5
2 =
1,200
composite factor = 2 × 5
4 =
1,250
composite factor = 2
6 × 3 × 7 =
1,344
composite factor = 2
3 × 5
2 × 7 =
1,400
composite factor = 2
2 × 3 × 5
3 =
1,500
composite factor = 2
6 × 5
2 =
1,600
composite factor = 2
4 × 3 × 5 × 7 =
1,680
composite factor = 2 × 5
3 × 7 =
1,750
composite factor = 3 × 5
4 =
1,875
composite factor = 2
4 × 5
3 =
2,000
composite factor = 2
2 × 3 × 5
2 × 7 =
2,100
composite factor = 2
6 × 5 × 7 =
2,240
composite factor = 2
5 × 3 × 5
2 =
2,400
composite factor = 2
2 × 5
4 =
2,500
composite factor = 3 × 5
3 × 7 =
2,625
composite factor = 2
4 × 5
2 × 7 =
2,800
composite factor = 2
3 × 3 × 5
3 =
3,000
composite factor = 2
5 × 3 × 5 × 7 =
3,360
composite factor = 2
2 × 5
3 × 7 =
3,500
composite factor = 2 × 3 × 5
4 =
3,750
composite factor = 2
5 × 5
3 =
4,000
composite factor = 2
3 × 3 × 5
2 × 7 =
4,200
composite factor = 5
4 × 7 =
4,375
composite factor = 2
6 × 3 × 5
2 =
4,800
composite factor = 2
3 × 5
4 =
5,000
composite factor = 2 × 3 × 5
3 × 7 =
5,250
composite factor = 2
5 × 5
2 × 7 =
5,600
composite factor = 2
4 × 3 × 5
3 =
6,000
composite factor = 2
6 × 3 × 5 × 7 =
6,720
composite factor = 2
3 × 5
3 × 7 =
7,000
composite factor = 2
2 × 3 × 5
4 =
7,500
composite factor = 2
6 × 5
3 =
8,000
composite factor = 2
4 × 3 × 5
2 × 7 =
8,400
composite factor = 2 × 5
4 × 7 =
8,750
composite factor = 2
4 × 5
4 =
10,000
composite factor = 2
2 × 3 × 5
3 × 7 =
10,500
composite factor = 2
6 × 5
2 × 7 =
11,200
composite factor = 2
5 × 3 × 5
3 =
12,000
composite factor = 3 × 5
4 × 7 =
13,125
composite factor = 2
4 × 5
3 × 7 =
14,000
composite factor = 2
3 × 3 × 5
4 =
15,000
composite factor = 2
5 × 3 × 5
2 × 7 =
16,800
composite factor = 2
2 × 5
4 × 7 =
17,500
composite factor = 2
5 × 5
4 =
20,000
composite factor = 2
3 × 3 × 5
3 × 7 =
21,000
composite factor = 2
6 × 3 × 5
3 =
24,000
composite factor = 2 × 3 × 5
4 × 7 =
26,250
composite factor = 2
5 × 5
3 × 7 =
28,000
composite factor = 2
4 × 3 × 5
4 =
30,000
composite factor = 2
6 × 3 × 5
2 × 7 =
33,600
composite factor = 2
3 × 5
4 × 7 =
35,000
composite factor = 2
6 × 5
4 =
40,000
composite factor = 2
4 × 3 × 5
3 × 7 =
42,000
composite factor = 2
2 × 3 × 5
4 × 7 =
52,500
composite factor = 2
6 × 5
3 × 7 =
56,000
composite factor = 2
5 × 3 × 5
4 =
60,000
composite factor = 2
4 × 5
4 × 7 =
70,000
composite factor = 2
5 × 3 × 5
3 × 7 =
84,000
composite factor = 2
3 × 3 × 5
4 × 7 =
105,000
composite factor = 2
6 × 3 × 5
4 =
120,000
composite factor = 2
5 × 5
4 × 7 =
140,000
composite factor = 2
6 × 3 × 5
3 × 7 =
168,000
composite factor = 2
4 × 3 × 5
4 × 7 =
210,000
composite factor = 2
6 × 5
4 × 7 =
280,000
composite factor = 2
5 × 3 × 5
4 × 7 =
420,000
composite factor = 2
6 × 3 × 5
4 × 7 =
840,000
140 factors (divisors)
What times what is 840,000?
What number multiplied by what number equals 840,000?
All the combinations of any two natural numbers whose product equals 840,000.
1 × 840,000 = 840,000
2 × 420,000 = 840,000
3 × 280,000 = 840,000
4 × 210,000 = 840,000
5 × 168,000 = 840,000
6 × 140,000 = 840,000
7 × 120,000 = 840,000
8 × 105,000 = 840,000
10 × 84,000 = 840,000
12 × 70,000 = 840,000
14 × 60,000 = 840,000
15 × 56,000 = 840,000
16 × 52,500 = 840,000
20 × 42,000 = 840,000
21 × 40,000 = 840,000
24 × 35,000 = 840,000
25 × 33,600 = 840,000
28 × 30,000 = 840,000
30 × 28,000 = 840,000
32 × 26,250 = 840,000
35 × 24,000 = 840,000
40 × 21,000 = 840,000
42 × 20,000 = 840,000
48 × 17,500 = 840,000
50 × 16,800 = 840,000
56 × 15,000 = 840,000
60 × 14,000 = 840,000
64 × 13,125 = 840,000
70 × 12,000 = 840,000
75 × 11,200 = 840,000
80 × 10,500 = 840,000
84 × 10,000 = 840,000
96 × 8,750 = 840,000
100 × 8,400 = 840,000
105 × 8,000 = 840,000
112 × 7,500 = 840,000
120 × 7,000 = 840,000
125 × 6,720 = 840,000
140 × 6,000 = 840,000
150 × 5,600 = 840,000
160 × 5,250 = 840,000
168 × 5,000 = 840,000
175 × 4,800 = 840,000
192 × 4,375 = 840,000
200 × 4,200 = 840,000
210 × 4,000 = 840,000
224 × 3,750 = 840,000
240 × 3,500 = 840,000
250 × 3,360 = 840,000
280 × 3,000 = 840,000
300 × 2,800 = 840,000
320 × 2,625 = 840,000
336 × 2,500 = 840,000
350 × 2,400 = 840,000
375 × 2,240 = 840,000
400 × 2,100 = 840,000
420 × 2,000 = 840,000
448 × 1,875 = 840,000
480 × 1,750 = 840,000
500 × 1,680 = 840,000
525 × 1,600 = 840,000
560 × 1,500 = 840,000
600 × 1,400 = 840,000
625 × 1,344 = 840,000
672 × 1,250 = 840,000
700 × 1,200 = 840,000
750 × 1,120 = 840,000
800 × 1,050 = 840,000
840 × 1,000 = 840,000
875 × 960 = 840,000
70 unique multiplications The final answer:
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