Prime Check API

POST https://api.findutils.com/api/tools/prime-check/execute

Check whether an integer is prime. For composite numbers, returns the prime factorisation. Supports inputs up to 2^53-1 but is only fast for n ≲ 10^12.

Needs an API key. Running a tool needs an API key. Keys are not for sale yet: ask for early access. About API keys

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Request body

application/json

n

integer required

Integer to test. Must be ≥ 2.

Example arguments

Verified

{
  "n": 360
}

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curl -X POST https://api.findutils.com/api/tools/prime-check/execute \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "n": 360
  }'

const response = await fetch('https://api.findutils.com/api/tools/prime-check/execute', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json', Authorization: 'Bearer YOUR_API_KEY' },
  body: JSON.stringify({"n":360}),
});
const data = await response.json();

import requests

response = requests.post(
    "https://api.findutils.com/api/tools/prime-check/execute",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    json={"n":360},
)
data = response.json()

$ch = curl_init('https://api.findutils.com/api/tools/prime-check/execute');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => ['Content-Type: application/json', 'Authorization: Bearer YOUR_API_KEY'],
    CURLOPT_POSTFIELDS => '{"n":360}',
    CURLOPT_RETURNTRANSFER => true,
]);
$data = json_decode(curl_exec($ch), true);

Also an MCP tool

Call prime_check from Claude, Cursor or any MCP client. Same arguments, same output.

https://mcp.findutils.com

MCP reference

Rate limit: 60 a minute, per IP
Auth: API key
REST id: prime-check
MCP name: prime_check
Category: Calculators
Machine-readable: openapi.json · markdown.md

Request body

Example arguments

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