你要找因式分解的通用公式?好像不存在
Answer (1 of 6): The function that counts the factors of a given number is called the divisor function. It's usually denoted by \sigma(n). If you only need to know the parity of \sigma(n), you're in luck: the number of divisors is odd if and only if n is a perfect square. Why? Divisors come in ...
-sxffff(lookingforjob) 2021-11-7