555

Do you want to work with 555 as a math problem, or something else (e.g., a number theory exercise, base conversions, etc.)? Here are some quick, exam-ready facts and ideas you can use.

Quick facts about 555

• Factorization: 555 = 3 × 5 × 37
• Divisors: 1, 3, 5, 15, 37, 111, 185, 555 (8 divisors)
• Sum of divisors: σ(555) = 912; sum of proper divisors = 912 − 555 = 357
• Euler’s totient: φ(555) = 288
• Base representations:
  • Binary: 1000101011₂
  • Hexadecimal: 0x22B
  • Base 7: 1422₇ (since 1·343 + 4·49 + 2·7 + 2 = 555)
• Roman numeral: DLV
• Simple modular facts: divisible by 3 and 5; 555 mod 7 = 2; 555 mod 11 = 5

Example exam-style problems (quick to practice)

• Show the prime factorization and count the divisors: 555 has 8 divisors.
• Compute φ(555) and explain the steps using the formula φ(n) = n ∏(1 − 1/p) over distinct primes p|n.
• If n = 555, what is 555 in base 7? (Answer: 1422₇)
• Find gcd(555, 735). (Answer: 15)
• Compute 555 modulo 13. (Answer: 9)

If you tell me your course focus (number theory, algebra, discrete math, etc.), I can tailor a set of targeted problems or walk you through a full solution to a specific question you have.