555

Not sure what you want with "555." If you’re prepping for math/number theory, here are quick facts and a few practice prompts about the number 555:

Quick facts

• Decimal: 555
• Prime factorization: 3 × 5 × 37
• Divisors: 1, 3, 5, 15, 37, 111, 185, 555 (8 divisors)
• Divisible by: 3 and 5 (since digits sum to 15 and ends with 5)
• Harshad (Niven) number in base 10: 555 ÷ (5+5+5) = 555 ÷ 15 = 37
• Binary: 1000101011
• Hexadecimal: 0x22B
• Roman numeral: DLV
• Palindrome and repdigit in base 10

Practice prompts (with quick answers you can check)

1. Find the prime factorization (given above): 3 × 5 × 37
2. List all divisors: 1, 3, 5, 15, 37, 111, 185, 555
3. Show divisibility by 3 and by 5: sum of digits is 15 → divisible by 3; ends with 5 → divisible by 5
4. Convert to binary, hex, and roman numerals (answers above)
5. How many ways can 555 be written as a sum of consecutive positive integers? (Hint: equals the number of odd divisors; here there are 8 ways)
6. Compute 555 × 9 and 555 ÷ 5: 555 × 9 = 4995; 555 ÷ 5 = 111

Would you like me to tailor this to a specific course (e.g., number theory, discrete math) or give full worked solutions for a couple of these prompts?