The notation "φ(9)" refers to the Euler's totient function, which counts the number of positive integers up to a given integer that are relatively prime to it. For the number 9, this means finding how many integers from 1 to 9 do not share any common factors with 9 other than 1. To calculate φ(9), we first identify the prime factorization of 9, which is 3^2. The formula for the totient function is φ(n) = n × (1 - 1/p) for each distinct prime factor p of n. Thus, φ(9) = 9 × (1 - 1/3) = 9 × (2/3) = 6. Therefore, φ(9) equals 6, indicating that there are six integers relatively prime to 9 within that range.