Is 642 is a composite number or not ?
- As we already know that, the number having factors 1 and the number itself is the prime number.
- And numbers having more than these two factors are the composite numbers.
- To check whether the number 642 is composite or not first we have to find its factors.
Contents
Factors of 642:
- If we have taken numbers from 1, 2, 3…for checking factors of 642, we found that 642 has factors 1, 2, 3, 6, 107, 214, 321 and 642. Hence, we must say that 642 is a composite number.
- Thus, 642 is the composite umber.
- If we multiply 642 by 1, 2, 3 then we get the multiples of 642 which are 642, 1284 and so on.
About the number 642:
- 642 has more than two factors which are 1, 2, 3, 6, 107, 214, 321 and 642 and hence it is the composite number.
- 642 is the even composite number and it is not the perfect square also.
- If we divide 642 by 1, 2, 3, 6, 107, 214, 321 and 642 then we get remainder as zero. Hence, 1, 2, 3, 6, 107, 214, 321 and 642 are the factors of 642.
Note:
- 642 is not the perfect square.
- Factors of 642: 1, 2, 3, 6, 107, 214, 321 and 642
- Prime factors of 642: 2, 3, 107
Conclusion:
- 642 is the composite number which has factors 1, 2, 3, 6, 107, 214, 321 and 642
- And hence, 642 is not the prime number.
Multiple Choice Questions:
1) 642 is a
a) Not a perfect square number
b) Even number
c) Composite number
d) all
Ans: d) all
2) The prime and composite factors of a composite number 642 are
a) 1
b) 2, 3, 107
c) 1, 6, 214, 321 and 642
d) 1, 2, 3, 6, 107, 214, 321 and 642
Ans: d) 1, 2, 3, 6, 107, 214, 321 and 642
3) 642 is the even composite number because
a) It has factors 1, 2, 3, 6, 107, 214, 321 and 642
b) More than two factors
c) Divisible by 2
d) all
Ans: d) all