555

Do you mean the number 555, or something else (like the 555 timer IC in electronics)? Here are quick math facts about 555 in case that’s what you want:

• Prime factorization: 3 × 5 × 37
• Divisors: 1, 3, 5, 15, 37, 111, 185, 555
• Sum of proper divisors: 357 (so 555 is deficient)
• Binary: 1000101011
• Hex: 0x22B
• Roman numeral: DLV
• It’s a palindromic repdigit (all digits 5)

If you meant something else (555 timer circuits, base conversions, or an exam problem), tell me the topic and I’ll tailor help or give you a quick practice question.