Phpexcel não suporta o valor inteiro longo
$objPHPExcel->getActiveSheet()->setCellValueExplicit('A1', '1234567890', PHPExcel_Cell_DataType::TYPE_STRING);
Dead Dolphin
$objPHPExcel->getActiveSheet()->setCellValueExplicit('A1', '1234567890', PHPExcel_Cell_DataType::TYPE_STRING);