treed's 3.p6 using Math::Prime

3.p6

# Solved in 16.5s
use Math::Prime;

sub factor_one($number) {
    my @primes := primes();
    for @primes ... * > sqrt $number -> $n {
        return $n if $number %% $n;
    }
}

my $number = 600851475143;
my $max = sqrt $number;

$number /= factor_one($number) while $number > $max;

say $number;