Is 399 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 399 is composite or not first we have to find its factors.
Contents
Factors of 399:
- If we have taken numbers from 1, 2, 3…for checking factors of 399, we found that 399 has factors 1, 3, 7, 19, 21, 57, 133 and 399. Hence, we must say that 399 is a composite number.
- Thus, 399 is the composite number.
- If we multiply 399 by 1, 2, 3 then we get the multiples of 399 which are 399, 798 and so on.
399 is a Composite number or Prime number
About the number 399:
- 399 has more than two factors which are 1, 3, 7, 19, 21, 57, 133 and 399 and hence it is the composite number.
- 399 is the odd composite number and it is not the perfect square also.
- If we divide 399 by 1, 3, 7, 19, 21, 57, 133 and 399 then we get remainder as zero. Hence, 1, 3, 7, 19, 21, 57, 133 and 399 are the factors of 399.
Note:
- 399 is not the perfect square.
- Factors of 399: 1, 3, 7, 19, 21, 57, 133 and 399
- Prime factors of 399: 3, 7, 19
Conclusion:
- 399 is the composite number which has factors 1, 3, 7, 19, 21, 57, 133 and 399.
- And hence, 399 is not the prime number.
Multiple Choice Questions:
1) 399 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 399 are
a) 1
b) 3, 7, 19
c) 1 and 399
d) 1, 21, 57, 133 and 399
Ans: b) 3, 7, 19
3) 399 is the odd composite number because
a) It has factors 1, 3, 7, 19, 21, 57, 133 and 399
b) It is divisible by 2
c) It is not divisible by 2
d) Both a and c
Ans: d) both a and c