Is 1215 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 1215 is composite or not first we have to find its factors.
Factors of 1215:
- If we have taken numbers from 1, 2, 3…for checking factors of 1215, we found that 1215 has factors 1, 3, 5, 9, 15, 27, 45, 81, 135, 243, 405 and 1215. Hence, we must say that 1215 is a composite number.
- Thus, 1215 is the composite number.
- If we multiply 1215 by 1, 2, 3 then we get the multiples of 1215 which are 1215, 2430 and so on.
1215 is a Composite number or Prime number
About the number 1215:
- 1215 has more than two factors which are 1, 3, 5, 9, 15, 27, 45, 81, 135, 243, 405 and 1215 and hence it is the composite number.
- 1215 is the odd composite number and it is not the perfect square also.
- If we divide 1215 by 1, 3, 5, 9, 15, 27, 45, 81, 135, 243, 405 and 1215 then we get remainder as zero. Hence, 1, 3, 5, 9, 15, 27, 45, 81, 135, 243, 405 and 1215 are the factors of 1215
Note:
- 1215 is not the perfect square.
- Factors of 1215: 1, 3, 5, 9, 15, 27, 45, 81, 135, 243, 405 and 1215
- Prime factors of 1215: 3, 5
Conclusion:
- 1215 is the composite number which has factors 1, 3, 5, 9, 15, 27, 45, 81, 135, 243, 405 and 1215.
- And hence, 1215 is not the prime number.
Multiple Choice Questions:
1) 1215 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 1215 are
a) 1
b) 3, 5
c) 1, 9, 15, 27, 45, 81, 135, 243, 405 and 1215
d) 1, 3, 5, 9, 15, 27, 45, 81, 135, 243, 405 and 1215
Ans: b) 3, 5
3) 1215 is the odd composite number because
a) It has factors 1, 3, 5, 9, 15, 27, 45, 81, 135, 243, 405 and 1215
b) It is divisible by 2
c) It is not divisible by 2
d) Both a and c
Ans: d) both a and c