To find all the divisors of the number 71,982:
- 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 71,982:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
71,982 = 2 × 33 × 31 × 43
71,982 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 71,982
- 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
composite factor = 3
2 =
9
composite factor = 2 × 3
2 =
18
composite factor = 3
3 =
27
prime factor =
31
prime factor =
43
composite factor = 2 × 3
3 =
54
composite factor = 2 × 31 =
62
composite factor = 2 × 43 =
86
composite factor = 3 × 31 =
93
composite factor = 3 × 43 =
129
composite factor = 2 × 3 × 31 =
186
composite factor = 2 × 3 × 43 =
258
This list continues below...
... This list continues from above
composite factor = 3
2 × 31 =
279
composite factor = 3
2 × 43 =
387
composite factor = 2 × 3
2 × 31 =
558
composite factor = 2 × 3
2 × 43 =
774
composite factor = 3
3 × 31 =
837
composite factor = 3
3 × 43 =
1,161
composite factor = 31 × 43 =
1,333
composite factor = 2 × 3
3 × 31 =
1,674
composite factor = 2 × 3
3 × 43 =
2,322
composite factor = 2 × 31 × 43 =
2,666
composite factor = 3 × 31 × 43 =
3,999
composite factor = 2 × 3 × 31 × 43 =
7,998
composite factor = 3
2 × 31 × 43 =
11,997
composite factor = 2 × 3
2 × 31 × 43 =
23,994
composite factor = 3
3 × 31 × 43 =
35,991
composite factor = 2 × 3
3 × 31 × 43 =
71,982
32 factors (divisors)
What times what is 71,982?
What number multiplied by what number equals 71,982?
All the combinations of any two natural numbers whose product equals 71,982.
1 × 71,982 = 71,982
2 × 35,991 = 71,982
3 × 23,994 = 71,982
6 × 11,997 = 71,982
9 × 7,998 = 71,982
18 × 3,999 = 71,982
27 × 2,666 = 71,982
31 × 2,322 = 71,982
43 × 1,674 = 71,982
54 × 1,333 = 71,982
62 × 1,161 = 71,982
86 × 837 = 71,982
93 × 774 = 71,982
129 × 558 = 71,982
186 × 387 = 71,982
258 × 279 = 71,982
16 unique multiplications The final answer:
(scroll down)