# Prime number checker

- Human page: https://happytails.ai/en/calculators/prime-number-checker/
- Markdown: https://happytails.ai/en/calculators/prime-number-checker.md
- Structured JSON: https://happytails.ai/agents/en/calculators/prime-number-checker/index.json
- Visibility: public

## Tool capabilities

| Property | Value |
| --- | --- |
| Tool ID | `prime-number-checker` |
| Category | calculators |
| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |
| Browser execution | Automatic updates after valid input or file selection. |
| Browser processing | Browser; see tool notes for network behavior. |
| HTTP API | Not callable through HTTP. |
| Browser-agent interface | run_current_tool |

### Implementation notes

Checks whole numbers from 0 to 1 trillion by exact trial division. 0 and 1 are neither prime nor composite.

### Inputs and settings

No free-text input is required. Use the file inputs and/or settings below.

| Setting | Meaning | Control type | Default | Constraints |
| --- | --- | --- | --- | --- |
| `value` | Whole number | number | 97 | min=0 max=1000000000000 step=1 |

### Browser-agent workflow

1. Open the human page in a browser that supports WebMCP.
2. Discover the interface exposed by that page; use its actual schema.
3. Select files on the page first when the tool requires files.
4. Call `run_current_tool` with valid input and settings.
5. Inspect the returned result or error and the displayed output. Retrieve files from the displayed download links.

Calls do not automatically copy or download results. Browser permissions still apply. Interface availability alone is not proof of successful execution.

### Planning specification

Zero and one are neither prime nor composite. Inputs must be integers within the stated range. This checker is intended for everyday arithmetic, not cryptographic key validation.

This describes intended requirements. Use the implementation notes, interface schema and observed output to determine current support.

### Complete machine-readable capability record

```json
{
  "id": "prime-number-checker",
  "category": "calculators",
  "built": true,
  "requirements": "Zero and one are neither prime nor composite. Inputs must be integers within the stated range. This checker is intended for everyday arithmetic, not cryptographic key validation.",
  "implementation": {
    "fields": [
      {
        "key": "value",
        "label": "Whole number",
        "value": 97,
        "type": "number",
        "min": 0,
        "max": 1000000000000,
        "step": 1
      }
    ],
    "input": false,
    "live": true,
    "presentation": "metrics",
    "note": "Checks whole numbers from 0 to 1 trillion by exact trial division. 0 and 1 are neither prime nor composite.",
    "experience": {
      "automatic": true,
      "single": false,
      "inputMaxLength": 1000000,
      "inputMode": "text",
      "label": "Your text",
      "placeholder": "Type or paste your input…",
      "help": "Change the input or settings to update your result. Results update as you type. Up to 1,000,000 characters.",
      "action": null
    },
    "mode": "automatic",
    "interactive": false
  },
  "execution": "Browser interface",
  "api": null,
  "browser_agent": {
    "supported": true,
    "name": "run_current_tool",
    "discovery": "WebMCP on the human page in a supporting browser",
    "verification": "See audit/API-AUDIT.md; availability is not verification"
  }
}
```

## Page guide

Check whether a whole number is prime.

How can we improve this tool?

Report a problem or share an idea.

Please leave out private information. Your message and the tool name go to our team via PostHog.

### How to use Prime number checker

1. Enter the values you want to calculate and choose the relevant units or settings.
2. The result updates as you type. Adjust the available settings if needed.
3. Review the result, then use Copy result or a download link when available.

## Useful next steps

- [Prime factorization calculator](https://happytails.ai/en/calculators/prime-factorization/) ([Markdown](https://happytails.ai/en/calculators/prime-factorization.md))

- [GCF calculator](https://happytails.ai/en/calculators/gcf-calculator/) ([Markdown](https://happytails.ai/en/calculators/gcf-calculator.md))

- [Lcm](https://happytails.ai/en/calculators/lcm/) ([Markdown](https://happytails.ai/en/calculators/lcm.md))

## How to use it

Enter a whole number between 0 and 1 trillion. The checker divides it by possible factors and shows its prime factorization.

### A worked example

97 is prime because its only positive divisors are 1 and 97. 91 is not prime: 7 × 13 = 91.

### What to know

Zero and one are neither prime nor composite. Inputs must be integers within the stated range. This checker is intended for everyday arithmetic, not cryptographic key validation.