/*
$fato(N,[chr]).[k]
returns the prime factorization of a number N, the chr is the ASCII value of the character that will separate the factors , if omitted the value used will be 32 (space). The k property indicates to whether or not use the power notation as shown in the examples below
$fato(36) : 2 2 3 3
$fato(50,44) : 2,5,5
$fato(8).k : 2^3
$fato(36,44).k : 2^2,3^2
*/
