555

Not sure what you want about 555. Do you mean math, electronics (555 timer), or something else? Here are quick math-related facts you might find useful for exams:

• Factorization: 555 = 3 × 5 × 37
• Also 555 = 15 × 37
• Divisible by: 3 and 5 (digits sum is 15; ends with 5)
• Divisors: 1, 3, 5, 15, 37, 111, 185, 555
• Roman numeral: DLV
• Binary: 1000101011
• Hexadecimal: 0x22B

If you want, tell me the topic (math, electronics, etc.) and I can tailor a quick explanation or practice problems.