Is 1821 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 1821 is composite or not first we have to find its factors.
Contents
Factors of 1821:
- If we have taken numbers from 1, 2, 3…for checking factors of 1821, we found that 1821 has factors 1, 3, 607 and 1821. Hence, we must say that 1821 is a composite number.
- Thus, 1821 is the composite number.
- If we multiply 1821 by 1, 2, 3 then we get the multiples of 1821 which are 1821, 3642 and so on.
1821 is a Composite number or Prime number
About the number 1821:
- 1821 has more than two factors which are 1, 3, 607 and 1821 and hence it is the composite number.
- 1821 is the odd composite number and it is not the perfect square also.
- If we divide 1821 by 1, 3, 607 and 1821 then we get remainder as zero. Hence, 1, 3, 607 and 1821 are the factors of 1821
Note:
- 1821 is not the perfect square.
- Factors of 1821: 1, 3, 607 and 1821
- Prime factors of 1821: 3, 607
Conclusion:
- 1821 is the composite number which has factors 1, 3, 607 and 1821.
- And hence, 1821 is not the prime number.
Multiple Choice Questions:
1) 1821 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 1821 are
a) 1
b) 3, 607
c) 1 and 1821
d) 1, 3, 607 and 1821
Ans: b) 1 and 1821
3) 1821 is the odd composite number because
a) It has factors 1, 3, 607 and 1821
b) It has more than two factors
c) It is not divisible by 2
d) all
Ans: d) all