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Prime Factorization Calculator

Math

Decompose any integer into its unique prime factors with exponential form, expanded notation, and step-by-step division steps.

Presets:
360 =
2^3 × 3^2 × 5
Expanded Product: 2 × 2 × 2 × 3 × 3 × 5
Status: Composite Number

Trial Division Steps

Step 1: 360 ÷ 2 = 180
Step 2: 180 ÷ 2 = 90
Step 3: 90 ÷ 2 = 45
Step 4: 45 ÷ 3 = 15
Step 5: 15 ÷ 3 = 5
Step 6: 5 ÷ 5 = 1

How This Calculator Works

The Fundamental Theorem of Arithmetic (Unique Factorization Theorem) states that every integer greater than 1 either is a prime number itself or can be represented uniquely as the product of prime numbers, up to the order of the factors. Prime factorization is the mathematical foundation of number theory, cryptography (such as RSA public-key encryption), and algorithmic hash functions.

📐 Canonical Prime Factorization Representation
n = p₁ᵃ¹ × p₂ᵃ² × p₃ᵃ³ × ... × pₖᵃᵏ | where p₁ < p₂ < ... < pₖ are primes
n: Positive integer greater than 1 being factored
pᵢ: Unique prime factor bases (e.g. 2, 3, 5, 7, 11, ...)
aᵢ: Multiplicity exponents indicating how many times prime pᵢ divides n
p₁ᵃ¹: Exponential compact notation for repeated prime factors

Key Mathematical Rules & Properties

Trial Division Method

Divide repeatedly by the smallest prime 2 until the quotient is odd, then test 3, 5, 7, and successive odd numbers up to the square root √n.

Prime Factor Tree & Ladder

Repeatedly branch composite numbers into smaller factors until every terminal leaf node is an indivisible prime number.

Coprime Verification

Two integers are coprime if their prime factorizations share no identical prime bases in common.

Divisor Count Formula

The total number of divisors of n equals (a₁ + 1)(a₂ + 1)...(aₖ + 1).

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Worked Example: Factorizing 360 into Primes

Find the prime factorization and canonical exponential form of 360.

  1. Divide by 2: 360 ÷ 2 = 180 (factor: 2)
  2. Divide by 2: 180 ÷ 2 = 90 (factor: 2)
  3. Divide by 2: 90 ÷ 2 = 45 (factor: 2)
  4. 45 is odd; divide by 3: 45 ÷ 3 = 15 (factor: 3)
  5. Divide by 3: 15 ÷ 3 = 5 (factor: 3)
  6. 5 is a prime number (factor: 5)
  7. Collect prime factors: 2, 2, 2, 3, 3, 5.
  8. Group into exponents: 2³ × 3² × 5¹.
Final Answer: 360 = 2³ × 3² × 5

Frequently Asked Questions

Why is 1 not considered a prime number?

If 1 were considered prime, the Fundamental Theorem of Arithmetic would fail to be unique, because any number could be written with arbitrarily many factors of 1 (e.g. 6 = 2 × 3 = 1 × 2 × 3 = 1 × 1 × 2 × 3).

How does prime factorization secure the Internet and banking?

RSA public-key cryptography relies on the mathematical asymmetry that multiplying two large primes together (e.g. 1024-bit primes) is instantaneous, but factoring their product back into primes is virtually impossible for modern supercomputers without knowing the private key.

What is the largest known prime number?

The largest known primes are Mersenne primes of the form 2ᵖ - 1, containing tens of millions of digits, discovered by the Great Internet Mersenne Prime Search (GIMPS).

Can every even number be expressed as the sum of two primes?

This is the Goldbach Conjecture (formulated in 1742), one of the oldest and most famous unsolved problems in mathematics.

Understanding your calculation

Method, example and limitations

How the calculation works

Prime factorization expresses a positive integer greater than one as a product of primes, grouping repeated primes as powers.

Example to check

360 = 2³ × 3² × 5. Multiplying those factors gives the original integer.

Before using the result

One is not prime and has no prime factorization. Zero and noninteger values are outside ordinary positive-integer prime factorization.

Calculation methodology · Report a result that needs review