555

What would you like to do with 555? Here are a few quick possibilities:

• Math facts:

  • Prime factorization: 555 = 3 × 5 × 37
  • Divisors: 1, 3, 5, 15, 37, 111, 185, 555
  • Binary: 1000101011
  • Sum of digits: 5+5+5 = 15, so divisible by 3 and 5 (hence by 15)
  • Roman numeral: DLV

• If you meant the 555 timer IC (electronics): I can explain how it works, and derive formulas for astable/monostable modes (e.g., f ≈ 1.44 / ((R_A + 2R_B) C) for astable).

Tell me which context you’re after, or share the exact problem you’re working on.