555

Not sure what you want with 555. Here are some quick math facts you can use for exam prep. Pick what you need or tell me your context and I’ll tailor problems.

• Decimal factorization: 555 = 3 × 5 × 37
• Divisors (8 total): 1, 3, 5, 15, 37, 111, 185, 555
• Divisibility: divisible by 3 and 5; not divisible by 9 or 11
• Roman numeral: 555 = DLV
• Binary: 555 = 1000101011₂
• Hexadecimal: 0x22B
• Related facts: 555 = 5 × 111 = 5 × (10^3 − 1)/9
• Example exam question ideas:
  • Find gcd(555, 420) and lcm(555, 420)
  • Determine the number of divisors of 555
  • Express 555 as a sum of two primes (if possible)
  • Convert 555 from decimal to binary/hex
  • Prove that 555 is not divisible by 7

How would you like to use 555? math, number theory, or something else (Roman numerals, conversions, etc.)? I can generate 3–5 practice questions at your level.