factorial jump function

例句：

1. 1. The number 24 is a factorial number.
   24是一个因数。
2. 2. In mathematics, the factorial of a number is its highest power that can be raised to any given number.
   在数学中，一个数的阶乘是它可以被任何给定数字的最高次方。
3. 3. The factorial of a prime number is always 1.
   质数的阶乘总是1。