Is 257 is a prime 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 257 is prime or not first we have to find its factors.
Contents
Factors of 257:
- If we have taken numbers from 1, 2, 3…for checking factors of 257, we found that 257 has factors 1 and the number 257 itself. Hence, we must say that 257 is a prime number.
- Thus, 257 is the prime number.
- Here, 257 is the odd prime number.
- If we multiply 257 by 1, 2, 3, then we get the multiples of 257 which are 257, 514, 771…and so on.
About the number 257:
- 257 has only two factors which are 1 and the number itself and hence 257 is the prime number.
- 257is the odd prime number and it is not the perfect square also.
- If we divide 257 by 1 and the number itself then we get remainder as zero. Hence, 1 and 257 are the factors of 257.
Note:
- 257 is not the perfect square.
- Factors of 257: 1 and 257
- Prime factors of 257: 257 (since, 257 is the only one prime number which is the factor of 257.)
Conclusion:
- 257is the prime number which has factors 1 and 257.
- And hence, 257 is the prime number.
Multiple Choice Questions:
1) 257 is a
a) odd number
b) Prime number
c) Composite number
d) Both a and b
Ans: d) both a and b
2) The prime factors of a prime number 257 are
a) 1
b) 257
c) Both a and b
d) 0
Ans: b) 257
3) 1 is the not prime factor of 257 because
a) It is the prime number
b) 1 is neither prime nor composite number
c) Both a and b
d) Given statement is false
Ans: b) 1 is neither prime nor composite number