555

Do you mean 555 in math, the 555 timer IC, or something else (e.g., Roman numerals, pop culture)? If you’re aiming for math, here are quick facts you can memorize:

• Prime factorization: 555 = 3 × 5 × 37
• Divisors: 1, 3, 5, 15, 37, 111, 185, 555
• Number of divisors: 8
• Sum of divisors: 912
• Binary: 1000101011₂
• Hex: 0x22B
• Roman numeral: DLV
• Notes: 555 is square-free (no repeated prime factors)

If you meant something else (like the 555 timer), tell me and I’ll tailor the notes. What would you like to focus on?