sentences:  For example, there are six positive integers less than 9 and relatively prime to it, so the totient of 9 is 6; there are two numbers less than 6 and relatively prime to it, so the totient of 6 is 2; and there is one number less than 2 and relatively prime to it, so the totient of 2 is 1; and , so 9 is a perfect totient number.The first few perfect totient numbers are
  
  In symbols, one writes
  for the iterated totient function.Then if "c" is the integer such that
  one has that "n" is a perfect totient number if
  
  It can be observed that many perfect totient are multiples of 3; in fact, 4375 is the smallest perfect totient number that is not divisible by 3.