diff --git a/src/applications/differential/parser/DifferentialChangesetParser.php b/src/applications/differential/parser/DifferentialChangesetParser.php
--- a/src/applications/differential/parser/DifferentialChangesetParser.php
+++ b/src/applications/differential/parser/DifferentialChangesetParser.php
@@ -906,11 +906,10 @@
         $shield = $renderer->renderShield(
           pht('This file was completely deleted.'));
       } else if ($this->changeset->getAffectedLineCount() > 2500) {
-        $lines = number_format($this->changeset->getAffectedLineCount());
         $shield = $renderer->renderShield(
           pht(
             'This file has a very large number of changes (%s lines).',
-            $lines));
+            new PhutilNumber($this->changeset->getAffectedLineCount())));
       }
     }
 
diff --git a/src/applications/diffusion/controller/DiffusionCommitController.php b/src/applications/diffusion/controller/DiffusionCommitController.php
--- a/src/applications/diffusion/controller/DiffusionCommitController.php
+++ b/src/applications/diffusion/controller/DiffusionCommitController.php
@@ -240,10 +240,10 @@
 
       $change_panel = new PHUIObjectBoxView();
       $header = new PHUIHeaderView();
-      $header->setHeader(pht('Changes (%d', number_format($count)));
+      $header->setHeader(pht('Changes (%s)', new PhutilNumber($count)));
       $change_panel->setID('toc');
-      if ($count > self::CHANGES_LIMIT && !$show_all_details) {
 
+      if ($count > self::CHANGES_LIMIT && !$show_all_details) {
         $icon = id(new PHUIIconView())
           ->setIconFont('fa-files-o');
 
diff --git a/src/applications/repository/management/PhabricatorRepositoryManagementReparseWorkflow.php b/src/applications/repository/management/PhabricatorRepositoryManagementReparseWorkflow.php
--- a/src/applications/repository/management/PhabricatorRepositoryManagementReparseWorkflow.php
+++ b/src/applications/repository/management/PhabricatorRepositoryManagementReparseWorkflow.php
@@ -241,8 +241,8 @@
         '**NOTE**: This script will queue tasks to reparse the data. Once the '.
         'tasks have been queued, you need to run Taskmaster daemons to '.
         'execute them.'."\n\n".
-        "QUEUEING TASKS (%d Commits):",
-        number_format(count($commits))));
+        "QUEUEING TASKS (%s Commits):",
+        new PhutilNumber(count($commits))));
     }
 
     $progress = new PhutilConsoleProgressBar();
diff --git a/src/applications/xhprof/controller/PhabricatorXHProfSampleListController.php b/src/applications/xhprof/controller/PhabricatorXHProfSampleListController.php
--- a/src/applications/xhprof/controller/PhabricatorXHProfSampleListController.php
+++ b/src/applications/xhprof/controller/PhabricatorXHProfSampleListController.php
@@ -57,7 +57,7 @@
         ->setHeader($sample->getRequestPath())
         ->setHref($this->getApplicationURI('profile/'.$file_phid.'/'))
         ->addAttribute(
-          number_format($sample->getUsTotal())." \xCE\xBCs");
+          new PhutilNumber($sample->getUsTotal())." \xCE\xBCs");
 
       if ($sample->getController()) {
         $item->addAttribute($sample->getController());
diff --git a/src/infrastructure/storage/management/workflow/PhabricatorStorageManagementProbeWorkflow.php b/src/infrastructure/storage/management/workflow/PhabricatorStorageManagementProbeWorkflow.php
--- a/src/infrastructure/storage/management/workflow/PhabricatorStorageManagementProbeWorkflow.php
+++ b/src/infrastructure/storage/management/workflow/PhabricatorStorageManagementProbeWorkflow.php
@@ -71,7 +71,7 @@
   private function formatSize($n, $o) {
     return sprintf(
       '%8.8s MB  %5.5s%%',
-      number_format($n / (1024 * 1024), 1),
+      new PhutilNumber($n / (1024 * 1024), 1),
       sprintf('%3.1f', 100 * ($n / $o)));
   }