555

Not sure what you want about “555.” Here are a few quick math notes and a small practice set you can use for exam prep.

Key facts about 555 (decimal)

• Prime factorization: 555 = 3 × 5 × 37
• Divisors: 1, 3, 5, 15, 37, 111, 185, 555
• Sum of all divisors σ(555) = 912; sum of proper divisors = 912 − 555 = 357 (so 555 is a deficient number)
• Roman numeral: DLV
• Hexadecimal: 0x22B
• Binary: 1000101011
• Base-7 representation: 1422_7

Quick practice problems

1. Verify the factorization: 555 = 3 × 5 × 37. Are there any repeated prime factors? (No; they are distinct.)
2. List all divisors and group them as pairs that multiply to 555 (e.g., 1 × 555). What are the other pairs?
3. Compute the sum of proper divisors and determine whether 555 is deficient, perfect, or abundant.
4. Convert 555 to hexadecimal and binary (already given above). Try doing without the hints.
5. Express 555 in Roman numerals (DLV).

Would you like me to tailor this to a specific exam topic (e.g., number theory, divisors, modular arithmetic) or create a longer set of practice questions with solutions?