555

Not sure what you want about 555. Do you want help with math, electronics (555 timer), or something else? Here are quick math notes in case that's what you need:

• Factorization: 555 = 3 × 5 × 37
• Divisors: 1, 3, 5, 15, 37, 111, 185, 555
• Parity and divisibility: odd; divisible by 3 and by 5 (digits sum is 15)
• Roman numeral: DLV
• Binary: 555 = 1000101011₂
• Hexadecimal: 0x22B

If you’d like, I can turn this into a couple of practice problems (factorization, divisor count, etc.) or switch to 555 timer basics (how it works, formula for frequency in astable/monostable modes). Which would you prefer?