❗ 阶乘计算器Factorial Calculator

使用说明与常见问题How-to & FAQ

「阶乘计算器」是什么？What is the Factorial Calculator?

计算 n!（支持到 5000!，大数精确结果），显示位数和末尾零个数。Calculate n! exactly (up to 5000!) with digit count and trailing zeros.

如何使用「阶乘计算器」？How do I use the Factorial Calculator?

在「阶乘计算器」中，填写「n」等参数，结果会随输入实时计算并显示在下方。In the Factorial Calculator: Fill in "n"; results are recalculated instantly as you type.

计算精度如何？How precise are the results?

「阶乘计算器」使用 JavaScript 双精度浮点数（约 15–16 位有效数字），部分功能使用 BigInt 处理大整数。The Factorial Calculator uses double-precision floating point (about 15–16 significant digits); some features use BigInt for large integers.

「阶乘计算器」免费吗？需要注册吗？Is the Factorial Calculator free? Do I need an account?

「阶乘计算器」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Factorial Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.