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Prime Checker
Check if a number is prime. This tool runs 100% locally in your browser.
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What is Prime Checker?
Determine if a number is Prime or Composite instantly. A prime number has only two factors: 1 and itself.
Useful for cryptography enthusiasts and math students.
When to Use This Tool
- 1Math homework verification
- 2Cryptography (primes are key to RSA)
- 3Number theory exploration
Examples
Input
17
Result
Prime
Input
18
Result
Composite (divisible by 2, 3...)
Frequently Asked Questions
Is 1 a prime number?
No, 1 is neither prime nor composite by definition.
Privacy & Security
Privacy is our priority. Unlike many other online tools, ToolsHub doesn't upload your data to any server. Whether you're processing sensitive text, calculating financial data, or generating passwords, everything stays in your browser.