360 = 2³ × 3² × 5

Prime factorization calculator

Any whole number up to a trillion: its prime factorisation, every divisor, how many there are, their sum and whether the number itself is prime.

From 2 to 1,000,000,000,000.

Short answer: 360 = 2³ × 3² × 5, which gives (3+1)(2+1)(1+1) = 24 divisors and their sum is 1,170. 97 is prime, so its only divisors are 1 and itself.

Why factorisation is useful

It is the base of fraction simplification, LCM and GCD, and the reason 1/6 and 1/4 share a denominator of 12. In computing it sizes hash tables and underpins modular arithmetic, which is why the difficulty of factoring large numbers keeps RSA keys safe.

Worked example

2,310 = 2 × 3 × 5 × 7 × 11 — five distinct primes, so it has 2⁵ = 32 divisors. Finding that by hand means dividing by 2, 3, 5, 7 and 11 in turn, which is exactly what the calculator does, stopping at the square root.

Prime factorisation questions

What is prime factorisation?

Writing a number as a product of primes: 360 = 2³ × 3² × 5. Every whole number above 1 has exactly one such factorisation, which is why it is called the fundamental theorem of arithmetic.

How does the calculator find the factors?

By trial division up to the square root of the number, which is exact and fast for anything a person types. It never guesses: the factorisation shown is the complete one, verified by multiplying the factors back.

How many divisors does a number have?

Multiply one more than each exponent in the prime factorisation. For 360 = 2³ × 3² × 5 there are (3+1)(2+1)(1+1) = 24 divisors, which the page lists as well as counts.

What is the next prime used for?

Sizing a hash table or RSA key material, and checking a number quickly against the prime above it. The page reports the smallest prime greater than your number, which is what those tables need.

Related tools