To find all the divisors of the number 8,921,240:
- 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 8,921,240:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
8,921,240 = 23 × 5 × 23 × 9,697
8,921,240 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 = (3 + 1) × (1 + 1) × (1 + 1) × (1 + 1) = 4 × 2 × 2 × 2 = 32
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 8,921,240
- 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
2 × 5 =
20
prime factor =
23
composite factor = 2
3 × 5 =
40
composite factor = 2 × 23 =
46
composite factor = 2
2 × 23 =
92
composite factor = 5 × 23 =
115
composite factor = 2
3 × 23 =
184
composite factor = 2 × 5 × 23 =
230
composite factor = 2
2 × 5 × 23 =
460
composite factor = 2
3 × 5 × 23 =
920
This list continues below...
... This list continues from above
prime factor =
9,697
composite factor = 2 × 9,697 =
19,394
composite factor = 2
2 × 9,697 =
38,788
composite factor = 5 × 9,697 =
48,485
composite factor = 2
3 × 9,697 =
77,576
composite factor = 2 × 5 × 9,697 =
96,970
composite factor = 2
2 × 5 × 9,697 =
193,940
composite factor = 23 × 9,697 =
223,031
composite factor = 2
3 × 5 × 9,697 =
387,880
composite factor = 2 × 23 × 9,697 =
446,062
composite factor = 2
2 × 23 × 9,697 =
892,124
composite factor = 5 × 23 × 9,697 =
1,115,155
composite factor = 2
3 × 23 × 9,697 =
1,784,248
composite factor = 2 × 5 × 23 × 9,697 =
2,230,310
composite factor = 2
2 × 5 × 23 × 9,697 =
4,460,620
composite factor = 2
3 × 5 × 23 × 9,697 =
8,921,240
32 factors (divisors)
What times what is 8,921,240?
What number multiplied by what number equals 8,921,240?
All the combinations of any two natural numbers whose product equals 8,921,240.
1 × 8,921,240 = 8,921,240
2 × 4,460,620 = 8,921,240
4 × 2,230,310 = 8,921,240
5 × 1,784,248 = 8,921,240
8 × 1,115,155 = 8,921,240
10 × 892,124 = 8,921,240
20 × 446,062 = 8,921,240
23 × 387,880 = 8,921,240
40 × 223,031 = 8,921,240
46 × 193,940 = 8,921,240
92 × 96,970 = 8,921,240
115 × 77,576 = 8,921,240
184 × 48,485 = 8,921,240
230 × 38,788 = 8,921,240
460 × 19,394 = 8,921,240
920 × 9,697 = 8,921,240
16 unique multiplications The final answer:
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