555

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• Number theory / math basics

  • Prime factorization: 555 = 3 × 5 × 37
  • Divisors: 1, 3, 5, 15, 37, 111, 185, 555 (8 divisors)
  • Totient: φ(555) = 288
  • Sum of divisors: σ(555) = 912
  • Binary: 1000101011
  • Octal: 1053
  • Hexadecimal: 0x22B
  • Base-3: 202120_3
  • Digital root: 6

• Roman numeral

  • DLV

• If you meant the 555 timer IC (electronics)

  • Astable: f = 1.44 / ((RA + 2RB)·C)
  • High/Low times: TH ≈ 0.693 (RA + RB) C, TL ≈ 0.693 RB C
  • Monostable: TH = 1.1 R C

• Other (year, code, etc.)

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