Is 861 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 861 is composite or not first we have to find its factors.
Contents
Factors of 861:
- If we have taken numbers from 1, 2, 3…for checking factors of 861, we found that 861 has factors 1, 3, 7, 21, 41, 123, 287 and 861. Hence, we must say that 861 is a composite number.
- Thus, 861 is the composite number.
- If we multiply 861 by 1, 2, 3 then we get the multiples of 861 which are 861, 1722 and so on.
861 is a Composite number or Prime number
About the number 861:
- 861 has more than two factors which are 1, 3, 7, 21, 41, 123, 287 and 861 and hence it is the composite number.
- 861 is the odd composite number and it is not the perfect square also.
- If we divide 861 by 1, 3, 7, 21, 41, 123, 287 and 861 then we get remainder as zero. Hence, 1, 3, 7, 21, 41, 123, 287 and 861 are the factors of 861
Note:
- 861 is not the perfect square.
- Factors of 861: 1, 3, 7, 21, 41, 123, 287 and 861
- Prime factors of 861: 3, 7, 21
Conclusion:
- 861 is the composite number which has factors 1, 3, 7, 21, 41, 123, 287 and 861.
- And hence, 861 is not the prime number.
Multiple Choice Questions:
1) 861 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 861 are
a) 1
b) 3, 7, 21
c) 1, 41, 123, 287 and 861
d) 1, 3, 7, 21, 41, 123, 287 and 861
Ans: b) 3, 7, 21
3) 861 is the odd composite number because
a) It has factors 1, 3, 7, 21, 41, 123, 287 and 861
b) It is divisible by 2
c) It is not divisible by 2
d) Both a and c
Ans: d) both a and c