555

Could you clarify what you’d like about 555? Here are a few quick possibilities:

• Math facts: prime factorization 3 × 5 × 37; number of divisors 8; sum of divisors 912; Euler’s totient φ(555) = 288.
• Representations: binary 1000101011; base-3 202120; base-7 1422; hexadecimal 0x22B; Roman numeral DLV.
• If you’re studying electronics: 555 timer IC basics and common configurations.

Tell me which angle you want, or the specific problem you’re working on.