555

Do you mean the number 555, or something else named 555 (like the 555 timer IC)? If you mean the number, here are quick facts and some practice ideas:

Quick facts about 555

• Decimal: 555
• Palindromic and repdigit (digits all the same)
• Prime factorization: 555 = 3 × 5 × 37
• Positive divisors: 1, 3, 5, 15, 37, 111, 185, 555
• Base representations:
  • Binary: 1000101011
  • Hexadecimal: 0x22B
  • Roman numerals: DLV
• Divisibility notes: sum of digits is 15, so divisible by 3 and by 5; not divisible by 9.

Practice questions

1. List all positive divisors of 555 and verify the prime factorization.
2. Convert 555 to binary and to hexadecimal.
3. Is 555 a prime number? Explain why or why not.
4. Compute 555 mod 7 and 555 mod 11.
5. If a price is 555 dollars and you add 8% tax, what is the final price?

If you actually meant the 555 timer IC or another topic, tell me the context (e.g., electronics, RC circuits, or a specific exam topic) and I’ll tailor questions and explanations.