555

Nice—here are quick facts about the number 555:

• It’s a palindrome and a repdigit (all digits are 5)
• Decimal factorization: 555 = 3 × 5 × 37
• Divisible by: 3, 5, 15, 37, 111, 185, 555
• Roman numeral: DLV
• Binary: 1000101011
• Octal: 1053
• Hex: 0x22B
• Base-3: 202120_3
• Harshad number (divisible by sum of digits): 555 ÷ 15 = 37

Would you like me to tailor this to a specific exam topic (e.g., number theory, bases, or numeral systems), or should I give you a quick 5-minute practice set using 555 as a theme? If you tell me your course and level, I can customize problems.