$ cat 892828_b.pl
#!/usr/bin/perl
use strict;
use warnings;

my ($M, $N) = (9999997, 3);
my $step=0;
my @ranges = map { my ($c,$d)=($step,$_*int($M/$N)); $step=$d; [ $c, $d-1 ] } 1 .. $N;
$ranges[-1][1]=$M;
print join(", ", map { "(".join("-",@{$_}).")" } @ranges), "\n";

$ perl 892828_b.pl
(0-3333331), (3333332-6666663), (6666664-9999997)