Formules

Calculatrice de décomposition en facteurs premiers

Entrez un entier de 2 à 1,000,000,000,000 pour voir ses facteurs premiers.

Résultat

Saisissez les valeurs et appuyez sur Calculer pour voir le résultat.

Formule

n=p1e1×p2e2×⋯n = p_1^{e_1} \times p_2^{e_2} \times \cdots

Every whole number above 1 is a product of primes in exactly one way (the fundamental theorem of arithmetic).

d(n)=(e1+1)(e2+1)⋯d(n) = (e_1 + 1)(e_2 + 1)\cdots

The number of divisors comes straight from the exponents.

Comment utiliser cette calculatrice

  1. Enter the number without separators, e.g. 360.
  2. Press Calculate. Each step divides out one prime.

Exemple corrigé

Prime factors of 360

360 ÷ 2³ = 45, 45 ÷ 3² = 5, and 5 is prime.

So 360 = 2³ × 3² × 5, with (3+1)(2+1)(1+1) = 24 divisors.

Questions fréquentes

What are the prime factors of 54 and of 24?

54 = 2 × 3³ (divide by 2 to get 27, then by 3 three times), and 24 = 2³ × 3 (halve three times to get 3). For all the factors, not just the primes, use the factors calculator.

Is 1 a prime number?

No. A prime has exactly two divisors, 1 and itself; 1 has only one.

Why is there an upper limit?

Factorising very large numbers takes a long time. Up to one trillion, the result is guaranteed and instant.

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