555

Do you mean 555 in math, electronics (555 timer), or something else? Here are quick notes you can use in math contexts:

• Prime factorization: 555 = 3 × 5 × 37
• Number of divisors: (1+1)(1+1)(1+1) = 8 Divisors: 1, 3, 5, 15, 37, 111, 185, 555
• Sum of divisors: σ(555) = (1+3)(1+5)(1+37) = 4 × 6 × 38 = 912
• Roman numeral: 555 = DLV
• Binary: 555 = 1000101011₂
• Hexadecimal: 555 = 0x22B
• Time interpretation: 5:55

If you’re studying electronics, a quick note on the 555 timer:

• It’s a versatile timer IC used in astable and monostable multivibrator circuits.
• For the common astable mode, frequency ≈ 1.44 / ((R1 + 2R2) C) and duty cycle depends on R1 and R2.
• It can be used for LED blinkers, PWM, tone generators, timers, etc.

Would you like:

• exam-style practice questions about 555 (divisors, modular arithmetic, base conversions),
• a deeper dive into the 555 timer, or something else?