The conversation between human and AI assistant.
How many of the first 1200 natural numbers are either prime to 6 or to 15?
I see. Is there a faster way to determine whether a number is prime to another number?
Yes. We can use Euler's totient function to calculate the number of natural numbers less than or equal to a given number N that are relatively prime to N. The value of Euler's totient function for N is denoted as φ(N).