Hello mgatto, and welcome to the Monastery!

From the information given, I cannot reproduce your problem:

#! perl
use strict;
use warnings;
use bigint;
use List::Util qw( max );
use Data::Dumper;

my @result = prime_factors(600_851_475_143);
#print Dumper \@result;
print max @result;

sub prime_factors
{
    my ($number) = @_;
    my  $divisor = 2;
    my  @factors;

    while ($number > 1)
    {
        if (($number % $divisor) == 0)
        {
            push @factors, $divisor;
            $number /= $divisor;
        }
        elsif ($divisor == 2)
        {
            ++$divisor;
        }
        else
        {
            $divisor += 2;
        }
    }

    return @factors;
}

[download]

Output:

12:58 >perl 609_SoPW.pl
6857
13:00 >

[download]

However, the problem you are seeing may be related to the problem I experienced recently with bignum and the range operator: see Strange interaction of bigint and foreach.

Hope that helps,

Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

In reply to Re: List::Util can't find max in array of BigInts by Athanasius
in thread List::Utils can't find max in array of BigInts by mgatto

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