To find all the divisors of the number 13,986:
- 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 13,986:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
13,986 = 2 × 33 × 7 × 37
13,986 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 = (1 + 1) × (3 + 1) × (1 + 1) × (1 + 1) = 2 × 4 × 2 × 2 = 32
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 13,986
- 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 × 3 =
6
prime factor =
7
composite factor = 3
2 =
9
composite factor = 2 × 7 =
14
composite factor = 2 × 3
2 =
18
composite factor = 3 × 7 =
21
composite factor = 3
3 =
27
prime factor =
37
composite factor = 2 × 3 × 7 =
42
composite factor = 2 × 3
3 =
54
composite factor = 3
2 × 7 =
63
composite factor = 2 × 37 =
74
composite factor = 3 × 37 =
111
This list continues below...
... This list continues from above
composite factor = 2 × 3
2 × 7 =
126
composite factor = 3
3 × 7 =
189
composite factor = 2 × 3 × 37 =
222
composite factor = 7 × 37 =
259
composite factor = 3
2 × 37 =
333
composite factor = 2 × 3
3 × 7 =
378
composite factor = 2 × 7 × 37 =
518
composite factor = 2 × 3
2 × 37 =
666
composite factor = 3 × 7 × 37 =
777
composite factor = 3
3 × 37 =
999
composite factor = 2 × 3 × 7 × 37 =
1,554
composite factor = 2 × 3
3 × 37 =
1,998
composite factor = 3
2 × 7 × 37 =
2,331
composite factor = 2 × 3
2 × 7 × 37 =
4,662
composite factor = 3
3 × 7 × 37 =
6,993
composite factor = 2 × 3
3 × 7 × 37 =
13,986
32 factors (divisors)
What times what is 13,986?
What number multiplied by what number equals 13,986?
All the combinations of any two natural numbers whose product equals 13,986.
1 × 13,986 = 13,986
2 × 6,993 = 13,986
3 × 4,662 = 13,986
6 × 2,331 = 13,986
7 × 1,998 = 13,986
9 × 1,554 = 13,986
14 × 999 = 13,986
18 × 777 = 13,986
21 × 666 = 13,986
27 × 518 = 13,986
37 × 378 = 13,986
42 × 333 = 13,986
54 × 259 = 13,986
63 × 222 = 13,986
74 × 189 = 13,986
111 × 126 = 13,986
16 unique multiplications The final answer:
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