GrandFather's suggestion of filter out the false matches afterwards is probably sufficient for you, and perhaps also more efficient (but do a Benchmark to be certain if time efficiency is an issue). However, maybe you need this in a larger pattern, and then you can use a negative look-ahead to avoid the mono-digit strings.

$_ = '2222222222 1234567890 123 0000000000 48192049281924 999999999999
+99';

print "$2\n" while /\b(?!(\d)\1+\b)(\d{10,}\b)/g;

__END__
1234567890
48192049281924
[download]

lodin