Is 1781 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 1781 is composite or not first we have to find its factors.
Contents
Factors of 1781:
- If we have taken numbers from 1, 2, 3…for checking factors of 1781, we found that 1781 has factors 1, 13, 137 and 1781. Hence, we must say that 1781 is a composite number.
- Thus, 1781 is the composite number.
- If we multiply 1781 by 1, 2, 3 then we get the multiples of 1781 which are 1781, 3562 and so on.
1781 is a Composite number or Prime number
About the number 1781:
- 1781 has more than two factors which are 1, 13, 137 and 1781 and hence it is the composite number.
- 1781 is the odd composite number and it is not the perfect square also.
- If we divide 1781 by 1, 13, 137 and 1781 then we get remainder as zero. Hence, 1, 13, 137 and 1781 are the factors of 1781
Note:
- 1781 is not the perfect square.
- Factors of 1781: 1, 13, 137 and 1781
- Prime factors of 1781: 13, 137
Conclusion:
- 1781 is the composite number which has factors 1, 13, 137 and 1781.
- And hence, 1781 is not the prime number.
Multiple Choice Questions:
1) 1781 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 1781 are
a) 1
b) 13, 137
c) 1 and 1781
d) 1, 13, 137 and 1781
Ans: b) 1 and 1781
3) 1781 is the odd composite number because
a) It has factors 1, 13, 137 and 1781
b) It has more than two factors
c) It is not divisible by 2
d) all
Ans: d) all