Check for Prime Number
Given a positive integer n, determine whether it is a prime number.
A prime number is a natural number greater than 1 that has exactly two distinct positive divisors: 1 and itself.
Return true if the given number is prime; otherwise, return false.
Example 1
Input
7
Output
true
Explanation
7 has exactly two positive divisors: 1 and 7.
Therefore, it is a prime number.
Example 2
Input
12
Output
false
Explanation
12 has more than two positive divisors: 1, 2, 3, 4, 6 and 12.
Therefore, it is not a prime number.
Constraints
Hints:
Hint 1
A number greater than 1 is prime if it has no divisors other than 1 and itself.
Hint 2
Instead of checking all numbers from 2 to n-1, it is sufficient to check divisors only up to √n.
Author & Technical Reviewer
Technically reviewed by: ExamAdda Technical Review Team
Technical Reviewers, ExamAdda
Software engineers at ExamAdda who check every article's definitions, complexity claims and code examples before and after publishing.
Published
Jul 21, 2026
Last updated
Aug 6, 2026
Content Verification Methodology
Definitions and complexity claims were checked against authoritative computer-science references. Code examples were compiled and tested with standard, boundary and edge-case inputs.
Expected Output