To find all the divisors of the number 198,800:
- 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 198,800:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
198,800 = 24 × 52 × 7 × 71
198,800 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) × (2 + 1) × (1 + 1) × (1 + 1) = 5 × 3 × 2 × 2 = 60
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 198,800
- 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 = 5
2 =
25
composite factor = 2
2 × 7 =
28
composite factor = 5 × 7 =
35
composite factor = 2
3 × 5 =
40
composite factor = 2 × 5
2 =
50
composite factor = 2
3 × 7 =
56
composite factor = 2 × 5 × 7 =
70
prime factor =
71
composite factor = 2
4 × 5 =
80
composite factor = 2
2 × 5
2 =
100
composite factor = 2
4 × 7 =
112
composite factor = 2
2 × 5 × 7 =
140
composite factor = 2 × 71 =
142
composite factor = 5
2 × 7 =
175
composite factor = 2
3 × 5
2 =
200
composite factor = 2
3 × 5 × 7 =
280
composite factor = 2
2 × 71 =
284
composite factor = 2 × 5
2 × 7 =
350
composite factor = 5 × 71 =
355
composite factor = 2
4 × 5
2 =
400
This list continues below...
... This list continues from above
composite factor = 7 × 71 =
497
composite factor = 2
4 × 5 × 7 =
560
composite factor = 2
3 × 71 =
568
composite factor = 2
2 × 5
2 × 7 =
700
composite factor = 2 × 5 × 71 =
710
composite factor = 2 × 7 × 71 =
994
composite factor = 2
4 × 71 =
1,136
composite factor = 2
3 × 5
2 × 7 =
1,400
composite factor = 2
2 × 5 × 71 =
1,420
composite factor = 5
2 × 71 =
1,775
composite factor = 2
2 × 7 × 71 =
1,988
composite factor = 5 × 7 × 71 =
2,485
composite factor = 2
4 × 5
2 × 7 =
2,800
composite factor = 2
3 × 5 × 71 =
2,840
composite factor = 2 × 5
2 × 71 =
3,550
composite factor = 2
3 × 7 × 71 =
3,976
composite factor = 2 × 5 × 7 × 71 =
4,970
composite factor = 2
4 × 5 × 71 =
5,680
composite factor = 2
2 × 5
2 × 71 =
7,100
composite factor = 2
4 × 7 × 71 =
7,952
composite factor = 2
2 × 5 × 7 × 71 =
9,940
composite factor = 5
2 × 7 × 71 =
12,425
composite factor = 2
3 × 5
2 × 71 =
14,200
composite factor = 2
3 × 5 × 7 × 71 =
19,880
composite factor = 2 × 5
2 × 7 × 71 =
24,850
composite factor = 2
4 × 5
2 × 71 =
28,400
composite factor = 2
4 × 5 × 7 × 71 =
39,760
composite factor = 2
2 × 5
2 × 7 × 71 =
49,700
composite factor = 2
3 × 5
2 × 7 × 71 =
99,400
composite factor = 2
4 × 5
2 × 7 × 71 =
198,800
60 factors (divisors)
What times what is 198,800?
What number multiplied by what number equals 198,800?
All the combinations of any two natural numbers whose product equals 198,800.
1 × 198,800 = 198,800
2 × 99,400 = 198,800
4 × 49,700 = 198,800
5 × 39,760 = 198,800
7 × 28,400 = 198,800
8 × 24,850 = 198,800
10 × 19,880 = 198,800
14 × 14,200 = 198,800
16 × 12,425 = 198,800
20 × 9,940 = 198,800
25 × 7,952 = 198,800
28 × 7,100 = 198,800
35 × 5,680 = 198,800
40 × 4,970 = 198,800
50 × 3,976 = 198,800
56 × 3,550 = 198,800
70 × 2,840 = 198,800
71 × 2,800 = 198,800
80 × 2,485 = 198,800
100 × 1,988 = 198,800
112 × 1,775 = 198,800
140 × 1,420 = 198,800
142 × 1,400 = 198,800
175 × 1,136 = 198,800
200 × 994 = 198,800
280 × 710 = 198,800
284 × 700 = 198,800
350 × 568 = 198,800
355 × 560 = 198,800
400 × 497 = 198,800
30 unique multiplications The final answer:
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