555

If you just typed 555 and want something exam-related, here are quick math facts and a few practice items you can use.

Facts about 555

• Prime factorization: 555 = 3 × 5 × 37
• Number of positive divisors: (1+1)(1+1)(1+1) = 8
• Divisible by: 3 and 5 (not by 9 or 7)
• Sum of all divisors (sigma): 912
• Sum of proper divisors: 912 − 555 = 357 → 555 is deficient (not perfect or abundant)
• Euler’s totient: φ(555) = 288
• Representations:
  • Binary: 1000101011
  • Hexadecimal: 0x22B
  • Roman numerals: DLV
• Base conversions:
  • 555 in base 3: 2021203

Practice questions (useful for quick checks)

1. List all positive divisors of 555.
2. Determine whether 555 is deficient, perfect, or abundant; show the sum of its proper divisors.
3. Compute σ(555) and φ(555).
4. Convert 555 to base 2 and base 16 (you can check against 0x22B and 1000101011).
5. (Optional) What is 555 in base 7?

If you tell me your course (number theory, algebra, discrete math, etc.) or what kind of exam problem you want, I can tailor a short set of questions or walkthroughs.