To find all the divisors of the number 791,680:
- 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 791,680:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
791,680 = 27 × 5 × 1,237
791,680 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 = (7 + 1) × (1 + 1) × (1 + 1) = 8 × 2 × 2 = 32
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 791,680
- 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
composite factor = 2
3 =
8
composite factor = 2 × 5 =
10
composite factor = 2
4 =
16
composite factor = 2
2 × 5 =
20
composite factor = 2
5 =
32
composite factor = 2
3 × 5 =
40
composite factor = 2
6 =
64
composite factor = 2
4 × 5 =
80
composite factor = 2
7 =
128
composite factor = 2
5 × 5 =
160
composite factor = 2
6 × 5 =
320
composite factor = 2
7 × 5 =
640
This list continues below...
... This list continues from above
prime factor =
1,237
composite factor = 2 × 1,237 =
2,474
composite factor = 2
2 × 1,237 =
4,948
composite factor = 5 × 1,237 =
6,185
composite factor = 2
3 × 1,237 =
9,896
composite factor = 2 × 5 × 1,237 =
12,370
composite factor = 2
4 × 1,237 =
19,792
composite factor = 2
2 × 5 × 1,237 =
24,740
composite factor = 2
5 × 1,237 =
39,584
composite factor = 2
3 × 5 × 1,237 =
49,480
composite factor = 2
6 × 1,237 =
79,168
composite factor = 2
4 × 5 × 1,237 =
98,960
composite factor = 2
7 × 1,237 =
158,336
composite factor = 2
5 × 5 × 1,237 =
197,920
composite factor = 2
6 × 5 × 1,237 =
395,840
composite factor = 2
7 × 5 × 1,237 =
791,680
32 factors (divisors)
What times what is 791,680?
What number multiplied by what number equals 791,680?
All the combinations of any two natural numbers whose product equals 791,680.
1 × 791,680 = 791,680
2 × 395,840 = 791,680
4 × 197,920 = 791,680
5 × 158,336 = 791,680
8 × 98,960 = 791,680
10 × 79,168 = 791,680
16 × 49,480 = 791,680
20 × 39,584 = 791,680
32 × 24,740 = 791,680
40 × 19,792 = 791,680
64 × 12,370 = 791,680
80 × 9,896 = 791,680
128 × 6,185 = 791,680
160 × 4,948 = 791,680
320 × 2,474 = 791,680
640 × 1,237 = 791,680
16 unique multiplications The final answer:
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