Is 1561 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 1561 is composite or not first we have to find its factors.
Contents
Factors of 1561:
- If we have taken numbers from 1, 2, 3…for checking factors of 1561, we found that 1561 has factors 1, 7, 223 and 1561. Hence, we must say that 1561 is a composite number.
- Thus, 1561 is the composite number.
- If we multiply 1561 by 1, 2, 3 then we get the multiples of 1561 which are 1561, 3122 and so on.
1561 is a Composite number or Prime number
About the number 1561:
- 1561 has more than two factors which are 1, 7, 223 and 1561 and hence it is the composite number.
- 1561 is the odd composite number and it is not the perfect square also.
- If we divide 1561 by 1, 7, 223 and 1561 then we get remainder as zero. Hence, 1, 7, 223 and 1561 are the factors of 1561
Note:
- 1561 is not the perfect square.
- Factors of 1561: 1, 7, 223 and 1561
- Prime factors of 1561: 7, 223
Conclusion:
- 1561 is the composite number which has factors 1, 7, 223 and 1561.
- And hence, 1561 is not the prime number.
Multiple Choice Questions:
1) 1561 is a
a) Even number
b) Prime number
c) Composite number
d) Both a and c
Ans: c) composite number
2) The non-prime factors of a composite number 1561 are
a) 1
b) 7, 223
c) 1 and 1561
d) 1, 7, 223 and 1561
Ans: b) 1 and 1561
3) 1561 is the odd composite number because
a) It has factors 1, 7, 223 and 1561
b) It has more than two factors
c) It is not divisible by 2
d) all
Ans: d) all