You could do something like

#!/usr/bin/perl

use bigint;

sub split32 {
    my $v = shift;
    my $n = shift;
    my $mask = 0xffffffff;
    my @b32;
    for (1..$n) {
        unshift @b32, $v & $mask;
        $v >>= 32;
    }
    return @b32;
}

my $n = 2;    # n x 32-bit

my $v = 1024;
for (1..6) {
    print unpack("B*", pack("N$n", split32($v, $n) )), "\n";
    $v *= 1024;
}
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Prints

0000000000000000000000000000000000000000000000000000010000000000
0000000000000000000000000000000000000000000100000000000000000000
0000000000000000000000000000000001000000000000000000000000000000
0000000000000000000000010000000000000000000000000000000000000000
0000000000000100000000000000000000000000000000000000000000000000
0001000000000000000000000000000000000000000000000000000000000000
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I've set the width to 64 bit in the example (to avoid line wrapping...), but in principle, you can also use larger widths, e.g. $n = 8 for 256 bits. Also, $v can of course be any integer number, and must not necessarily be a power of 1024.

Update: BTW, don't indiscriminately enable bigint for your entire program... it can slow down things considerably! Limit its scope to where you really need it — by putting extra blocks around those sections:

{
    use bigint;

    # code that needs it...
}

# other code...
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