How many factors (divisors) does 120 have, including 1 and the number itself?

💡 Solution & Explanation

Write the number as a product of primes: 120 = 2^3 × 3 × 5. A factor can use each prime from power 0 up to its full power, so the number of factors = (3 + 1) × (1 + 1) × (1 + 1) = 16. Multiplying (exponent + 1) for each prime is much faster than listing every factor.