555

Do you mean the number 555 (math) or something else (like the 555 timer IC in electronics)? If you want math, here are quick facts about 555:

• Prime factorization: 555 = 3 × 5 × 37
• It's a repdigit palindrome (three 5s) and divisible by 15
• Roman numeral: DLV
• Base representations: binary 1000101011₂, hexadecimal 0x22B, octal 1053₈
• Euler’s totient: φ(555) = 288
• Number of divisors: 8 (1, 3, 5, 15, 37, 111, 185, 555)
• Sum of divisors: σ(555) = 912

If you want, I can create practice problems or walk through a proof or a specific calculation. What would you like?