Is 561 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 561 is composite or not first we have to find its factors.
Contents
Factors of 561:
- If we have taken numbers from 1, 2, 3…for checking factors of 561, we found that 561 has factors 1, 3, 11, 17, 33, 51, 187 and 561. Hence, we must say that 561 is a composite number.
- Thus, 561 is the composite number.
- If we multiply 561 by 1, 2, 3 then we get the multiples of 561 which are 561, 1122 and so on.
561 is a Composite number or Prime number
About the number 561:
- 561 has more than two factors which are 1, 3, 11, 17, 33, 51, 187 and 561 and hence it is the composite number.
- 561 is the odd composite number and it is not the perfect square also.
- If we divide 561 by 1, 3, 11, 17, 33, 51, 187 and 561 then we get remainder as zero. Hence, 1, 3, 11, 17, 33, 51, 187 and 561 are the factors of 561.
Note:
- 561 is not the perfect square.
- Factors of 561: 1, 3, 11, 17, 33, 51, 187 and 561
- Prime factors of 561: 3, 11, 17
Conclusion:
- 561 is the composite number which has factors 1, 3, 11, 17, 33, 51, 187 and 561.
- And hence, 561 is not the prime number.
Multiple Choice Questions:
1) 561 is a
a) odd number
b) Prime number
c) Composite number
d) Both a and c
Ans: d) both a and c
2) The prime factors of a composite number 561 are
a) 1
b) 3, 11, 17
c) 1, 33, 51, 187 and 561
d) 1, 3, 11, 17, 33, 51, 187 and 561
Ans: b) 3, 11, 17
3) 561 is the odd composite number because
a) It has factors 1, 3, 11, 17, 33, 51, 187 and 561
b) It is divisible by 2
c) It is not divisible by 2
d) Both a and c
Ans: d) both a and c