Is 1581 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 1581 is composite or not first we have to find its factors.
Contents
Factors of 1581:
- If we have taken numbers from 1, 2, 3…for checking factors of 1581, we found that 1581 has factors 1, 3, 17, 31, 51, 93, 527 and 1581. Hence, we must say that 1581 is a composite number.
- Thus, 1581 is the composite number.
- If we multiply 1581 by 1, 2, 3 then we get the multiples of 1581 which are 1581, 3162 and so on.
1581 is a Composite number or Prime number
About the number 1581:
- 1581 has more than two factors which are 1, 3, 17, 31, 51, 93, 527 and 1581 and hence it is the composite number.
- 1581 is the odd composite number and it is not the perfect square also.
- If we divide 1581 by 1, 3, 17, 31, 51, 93, 527 and 1581 then we get remainder as zero. Hence, 1, 3, 17, 31, 51, 93, 527 and 1581 are the factors of 1581
Note:
- 1581 is not the perfect square.
- Factors of 1581: 1, 3, 17, 31, 51, 93, 527 and 1581
- Prime factors of 1581: 3, 17, 31
Conclusion:
- 1581 is the composite number which has factors 1, 3, 17, 31, 51, 93, 527 and 1581.
- And hence, 1581 is not the prime number.
Multiple Choice Questions:
1) 1581 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 1581 are
a) 1
b) 3, 17, 31
c) 1, 51, 93, 527 and 1581
d) 1, 3, 17, 31, 51, 93, 527 and 1581
Ans: b) 1, 51, 93, 527 and 1581
3) 1581 is the odd composite number because
a) It has factors 1, 3, 17, 31, 51, 93, 527 and 1581
b) It has more than two factors
c) It is not divisible by 2
d) all
Ans: d) all