2.1k views
The number of distinct positive integral factors of $2014$ is _____________
edited | 2.1k views
0
0

@Prudhvi Phanindra

please take care of category of questions

First do prime factorization of 2014 - 21 x 191 x 531

Now to get a factor of 2014, we can choose any combination of the prime factors including 0. i.e; 2and 21 are possible and similarly for other prime factors also, there are 2 possibilities. So, total number of positive integral factors

$= 2 \times 2 \times 2 = 8$

(When all the powers of prime factors are 0, we get 1 and when all the powers are maximum, we get the given number.)

selected by
0
What is done after prime factorization? I did not understand, Is there a difference between prime factors and integral factors?
+5
Any integral factor will be a multiple of prime factors. So, if we decompose a number into a multiple of prime factors, number of integral factors will be the number of ways in which we can multiply the prime factors.
+5
How to think in exam 1007= 19*53 ?
+3
For numbers like 1007, where the factors are not clear, the following strategy should be employed.

Suppose we want to find the factors of 1007, now we know 1007 can be written as x*y (x, y != 1 or 1007) if 1007 has some prime factor. It is not very hard to see that both x and y cannot be greater than $\left \lfloor \sqrt{1007} \right \rfloor$ because if both are greater than $\left \lfloor \sqrt{1007} \right \rfloor$ then x*y > 1007 but x*y = 1007.

So one of them has to be less than $\left \lfloor \sqrt{1007} \right \rfloor$ . Now if we can find which is this no. less than $\left \lfloor \sqrt{1007} \right \rfloor$, we can determine x*y. Here $\left \lfloor \sqrt{1007} \right \rfloor$ = 31. So, we check for divisibility with 31,29,23,19. We find 1007 is divisible by 19 and = 19*53. We know 53 is prime. So 1007 = 19*53.
2014 = 2 x 19 x 53

total  positive integral factor=(2x2x2)=8
+1 vote
the factors are 1, 2, 19, 38, 53, 106, 1007 and 2014. So the total makes it 8 number of integral factors.
edited
0
Integral factor is the no way how can you multiply prime factor @Regina here 107 is not true it will 1007 please correct it. @Arjun sir explained it in very good way please check this.
0

is there any general formula for this .. ?

0

No. It is simple prime factorization
0
okzz..
0
good