555

Do you mean the number 555, or something else (e.g., the 555 timer IC)? Here are quick facts if you meant the number 555:

• Prime factorization: 555 = 3 × 5 × 37
• Divisors: 1, 3, 5, 15, 37, 111, 185, 555
• φ(555) = 288
• It’s divisible by 3, 5 (and hence by 15); sum of digits is 15
• Roman numeral: DLV
• Binary: 1000101011₂
• Hexadecimal: 0x22B
• Base-7 representation: 1422₇

If you had a specific exam task in mind (e.g., factorization, modular arithmetic, or a problem involving the 555 timer), tell me and I’ll tailor the help.