555

Do you mean the number 555 (for math) or the Thai internet slang "555" (laughing)? If you want math help, here are a few quick facts and practice problems:

Quick facts about 555

• Prime factorization: 555 = 3 × 5 × 37
• Sum of digits: 5 + 5 + 5 = 15 (digital root = 6)
• 555 is a palindrome and a repdigit (same digit repeated)
• 555^2 = 308,025
• 555^3 = 170,953,875
• 555 = 5 × 111 = 5 × 3 × 37

Practice problems

1. Find gcd(555, 3000). Answer: 15
2. If n = 555 × 7, what is n? Answer: 3,885
3. How many multiples of 37 lie between 1 and 555? Answer: floor(555/37) = 15
4. What is the remainder when 555^2 is divided by 7? (Hint: use modular arithmetic) Answer: 555 ≡ 6 (mod 7); 6^2 ≡ 36 ≡ 1 (mod 7), so remainder is 1

If you meant the slang, I can explain its usage or cultural context. Tell me what you’re studying (e.g., number theory, algebra, etc.), and I’ll tailor more problems.