质数检测
检查一个数是否为质数，并查看它的因数和附近的质数。
在您的浏览器中运行。您的文件不会离开设备。 了解如何验证
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使用方法
- 1填写各项
输入数字或选择所需选项。
- 2查看结果
更改任何值时，答案会立即更新。
- 3使用结果
复制结果或记下来。不会向任何地方发送任何内容。
About this tool
Enter a whole number up to one trillion. You see whether it is prime, its prime factorisation if it is not, and the nearest prime numbers before and after it.
When to use it
Check if a number is prime and see its factors and nearby primes.
Tips
A prime has exactly two factors, one and itself.
Privacy
Everything runs in your browser, so your data is not uploaded or stored.
Handy facts
The first primes are 2, 3, 5, 7, 11, 13, 17, 19, 23 and 29. Every number above 1 is either prime or a product of primes, which is why primes are called the building blocks of numbers.
计算示例
With the boxes at their starting values (Whole number: 97), the tool shows: Prime factors: 97; Previous prime: 89; Next prime: 101; Result: Prime number. Change any box to see your own numbers. The result updates as you type, and nothing leaves your browser.
获得最佳结果的提示
在相信结果之前先检查每一个输入项，因为一个错误的数字就会改变整个答案。请使用工资单、账单、证书或合同上的准确数字，并记下计算日期。税率、门槛和规则会不时变化，因此对于税费和法律事务，请将结果视为估算，并与本页注明的官方来源核对。您可以尝试任意多个方案；不会保存或发送任何内容，刷新页面会清空输入。
要点
- 分类: 日常工具
- 在浏览器中运行，无需注册，无需上传。
- 您输入的信息保留在设备上。
- 提供多种语言。
- 内容最后审核日期:
常见问题
What is a prime number?
A number greater than 1 that can only be divided by 1 and itself, such as 2, 3, 5, 7 and 11.
Is 1 a prime?
No. A prime has exactly two different divisors, and 1 has only one.
Is 1 prime?
No.
Is 2 prime?
Yes, it is the only even prime.
How can I test a number by hand?
Divide it by primes up to its square root. If none divide it, it is prime.