2024年4月26日 · Euler’s theorem or Euler’s totient theorem is an expansion of Fermat’s little theorem, which states that: If an integer ‘a’ is relatively prime to any positive integer ‘n,’ and φ (n) is the number of positive integers (≤ n) that are relatively prime to ‘n,’ then. a φ (n) ≡ 1 (mod n) Here, n = x p y q z r, for any natural number ‘n’.