555

Do you want math properties of the number 555, or something else (e.g., electronics 555 timer, phone keypad, or Roman numerals)? Here are quick facts you can use:

• 555 = 3 × 5 × 37 (composite)
• Roman numeral: DLV
• Binary: 1000101011
• Hexadecimal: 0x22B
• In words: five hundred fifty-five
• On a classic phone keypad (multi-tap), 555 corresponds to the letter L (press 5 three times)
• Common usage: 555 timer IC in electronics (astable/monostable circuits)

If you want, I can turn this into a few exam-style questions (e.g., divisors of 555, convert bases, or Roman numeral conversion). Which direction should we go?