Instantly identify prime, composite, or special numbers. Supports batch checking and mathematical property analysis.
Enter a number to check
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Struggling to quickly determine the properties of an integer? This tool uses number theory algorithms to accurately analyze your input and classify it into one of three categories: prime, composite, or other. A prime number is a natural number greater than 1 that is only divisible by 1 and itself (e.g., 2, 3). A composite number is a positive integer that has at least one divisor other than 1 and itself (e.g., 4, 6). All other numbers, such as 1, 0, and negative numbers, are classified as special categories (neither).
Q: Is 1 a prime number?
No. According to mathematical definitions, 1 is neither prime nor composite. The tool will classify it as "Other".
Q: Can negative numbers be identified as prime numbers?
No. The definition of prime numbers only applies to natural numbers greater than 1. All negative numbers and 0 are categorized as "Other".
The tool only accepts integer inputs; non-integer values will cause calculation errors. We recommend processing no more than 100 numbers at a time. Extremely large integers (exceeding 10^15) may impact calculation efficiency. The classification strictly follows mathematical definitions and does not apply to non-standard values like complex numbers.
For math education, we recommend using this tool alongside definition explanations: entering "2 9 15" demonstrates typical examples of primes [2] and composites [9, 15]. Developers should note that this tool does not provide an API; for large-scale batch processing, we recommend submitting in smaller batches. All calculations are performed locally in your browser, ensuring zero data upload risks.
