555

Do you want math facts about the number 555? Here are a few quick ones:

• Prime factorization: 555 = 3 × 5 × 37 (so it’s composite).
• Divisors: 1, 3, 5, 15, 37, 111, 185, 555 (there are 8 divisors).
• Roman numeral: 555 = DLV.
• Decimal representation of its reciprocal: 1/555 = 0.001801801801… (repeats every 3 digits: 801).
• Optional extras: sum of digits is 15 (digital root 6); in binary, 555 = 1000101011.

Which fact would you like to use for an exam problem, or would you like me to create a practice question?