Is 1815 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 1815 is composite or not first we have to find its factors.
Contents
Factors of 1815:
- If we have taken numbers from 1, 2, 3…for checking factors of 1815, we found that 1815 has factors 1, 3, 5, 11, 15, 33, 55, 121, 165, 363, 605 and 1815. Hence, we must say that 1815 is a composite number.
- Thus, 1815 is the composite number.
- If we multiply 1815 by 1, 2, 3 then we get the multiples of 1815 which are 1815, 3630 and so on.
1815 is a Composite number or Prime number
About the number 1815:
- 1815 has more than two factors which are 1, 3, 5, 11, 15, 33, 55, 121, 165, 363, 605 and 1815 and hence it is the composite number.
- 1815 is the odd composite number and it is not the perfect square also.
- If we divide 1815 by 1, 3, 5, 11, 15, 33, 55, 121, 165, 363, 605 and 1815 then we get remainder as zero. Hence, 1, 3, 5, 11, 15, 33, 55, 121, 165, 363, 605 and 1815 are the factors of 1815
Note:
- 1815 is not the perfect square.
- Factors of 1815: 1, 3, 5, 11, 15, 33, 55, 121, 165, 363, 605 and 1815
- Prime factors of 1815: 3, 5, 11
Conclusion:
- 1815 is the composite number which has factors 1, 3, 5, 11, 15, 33, 55, 121, 165, 363, 605 and 1815.
- And hence, 1815 is not the prime number.
Multiple Choice Questions:
1) 1815 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 1815 are
a) 1
b) 3, 5, 11
c) 1, 15, 33, 55, 121, 165, 363, 605 and 1815
d) 1, 3, 5, 11, 15, 33, 55, 121, 165, 363, 605 and 1815
Ans: b) 1, 15, 33, 55, 121, 165, 363, 605 and 1815
3) 1815 is the odd composite number because
a) It has factors 1, 3, 5, 11, 15, 33, 55, 121, 165, 363, 605 and 1815
b) It has more than two factors
c) It is not divisible by 2
d) all
Ans: d) all