質數檢測
檢查一個數是否為質數，並檢視它的因數和附近的質數。
在您的瀏覽器中執行。您的檔案不會離開裝置。 瞭解如何驗證
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使用方法
- 1填寫各項
輸入數字或選擇所需選項。
- 2檢視結果
更改任何值時，答案會立即更新。
- 3使用結果
複製結果或記下來。不會向任何地方傳送任何內容。
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.
計算示例
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.
獲得最佳結果的提示
在相信結果之前先檢查每一個輸入項，因為一個錯誤的數字就會改變整個答案。請使用工資單、賬單、證書或合同上的準確數字，並記下計算日期。稅率、門檻和規則會不時變化，因此對於稅費和法律事務，請將結果視為估算，並與本頁註明的官方來源核對。您可以嘗試任意多個方案；不會儲存或傳送任何內容，重新整理頁面會清空輸入。
要點
- 分類: 日常工具
- 在瀏覽器中執行，無需註冊，無需上傳。
- 您輸入的資訊保留在裝置上。
- 提供多種語言。
- 內容最後稽核日期:
常見問題
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.