factor
factor(n) > Dict
Compute the prime factorization of an integer n
. Returns a dictionary. The
keys of the dictionary correspond to the factors, and hence are of the same type
as n
. The value associated with each key indicates the number of times the
factor appears in the factorization.
julia> factor(100) # == 2*2*5*5
Dict{Int64,Int64} with 2 entries:
2 => 2
5 => 2
Examples

Factorize an integer:
julia> factor(100) Dict{Int64, Int64} with 2 entries: 2 => 2 5 => 2
This example calculates the prime factorization of the integer 100 and returns a dictionary where the keys represent the factors and the values indicate the number of times each factor appears in the factorization.

Factorize a large number:
julia> factor(9876543210) Dict{Int64, Int64} with 4 entries: 2 => 1 3 => 2 5 => 1 3607 => 1
It computes the prime factorization of a large number (9876543210 in this case) and returns a dictionary with the prime factors and their multiplicities.
 Factorize a prime number:
julia> factor(17) Dict{Int64, Int64} with 1 entry: 17 => 1
When a prime number is provided, the function returns a dictionary with only one entry representing the prime factor itself.
Common mistake example:
julia> factor(0)
ERROR: DomainError("0 is not a positive integer.")
In this example, the input provided is not a positive integer, which results in a DomainError
. The factor
function expects a positive integer as input. Make sure to provide a valid positive integer to avoid such errors.
See Also
abs2, beta, binomial, ceil, cell, cross, ctranspose, ctranspose!, cummin, cumprod, cumprod!, cumsum, cumsum!, cumsum_kbn, div, divrem, eigfact, eigfact!, eigmin, eps, erf, erfc, erfcinv, erfcx, erfi, erfinv, exp, exp10, exp2, expm1, exponent, factor, factorial, factorize, floor, gcd, invmod, log, log10, log1p, log2, logspace, max, min, mod, mod1, modf, next, nextpow, nextprod, num, primes, primesmask, prod, realmin, sqrt, sum!, sumabs, sumabs!, sumabs2, sumabs2!,User Contributed Notes
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