555

Nice, a quick math look at 555. Here are some useful facts and quick problems you can use for exam prep:

Core facts

• Prime factorization: 555 = 3 × 5 × 37
• Divisors: Since it has three distinct prime factors, number of divisors = (1+1)(1+1)(1+1) = 8
• Divisible by: 3 and 5 (sum of digits = 15, ends with 5)
• Roman numeral: DLV
• Binary: 555 = 1000101011₂
• Hexadecimal: 555 = 0x22B
• Optional quick check: gcd(555, 1000) = 5

Possible quick practice problems

• Problem 1: Verify the factorization by multiplying back: 3 × 5 × 37 = 555.
• Problem 2: List all divisors of 555.
• Problem 3: Convert 555 seconds to minutes and seconds.
• Problem 4: Express 555 in base 7.
• Problem 5: Compute 555 mod 9 and mod 11.

If you tell me your subject (algebra, number theory, programming, etc.) I can tailor a small 5-question quiz around 555 with solutions.