Error on Openshift while trying to launch NodeJS for an Express app

I made a simple web app with Expressjs and Nodejs (using MEAN.js stack). I pulled my web app from git to my Openshift server using SSH access.

And after installing all modules, I configured my MongoDB URI, and then in order to launch my server I do this command on my project server :

NODE_ENV=production npm start

And I get this error :

      Fatal error: listen EACCES
      Warning:  Used --force, continuing.


      Running "nodemon:dev" (nodemon) task
  [nodemon] v1.0.20
  [nodemon] to restart at any time, enter `rs`
  [nodemon] watching: app/views/**/*.* gruntfile.js server.js config/**/*.js app/**/*.js
  [nodemon] starting `node --debug server.js`
  debugger listening on port 5858
  Failed to open socket on port 5858, waiting 1000 ms before retrying

   Application loaded using the "production" environment configuration

  js-bson: Failed to load c++ bson extension, using pure JS version
  Failed to open socket on port 5858, waiting 1000 ms before retrying
  Failed to open socket on port 5858, waiting 1000 ms before retrying
  Failed to open socket on port 5858, waiting 1000 ms before retrying
  Failed to open socket on port 5858, waiting 1000 ms before retrying
  Failed to load c++ bson extension, using pure JS version
  Failed to open socket on port 5858, waiting 1000 ms before retrying
  Failed to open socket on port 5858, waiting 1000 ms before retrying
  MEAN.JS application started on port 8081

  events.js:72
          throw er; // Unhandled 'error' event
                ^
  Error: listen EACCES
      at errnoException (net.js:901:11)
      at Server._listen2 (net.js:1020:19)
      at listen (net.js:1061:10)
      at Server.listen (net.js:1135:5)
      at Function.app.listen (/var/lib/openshift/53be9cb55004467d130002a4/app-deployments/2014-07-10_10-01-30.769/MeanApp/node_modules/express/lib/application.js:532:24)
      at Object.<anonymous> (/var/lib/openshift/53be9cb55004467d130002a4/app-deployments/2014-07-10_10-01-30.769/MeanApp/server.js:25:5)
      at Module._compile (module.js:456:26)
      at Object.Module._extensions..js (module.js:474:10)
      at Module.load (module.js:356:32)
      at Function.Module._load (module.js:312:12)
  [nodemon] app crashed - waiting for file changes before starting...

In order to fix it I googled the error and looked in StackOverflow for solutions. It seemed to be a port problem so I tried to change port to 8080, 8081, 3000, but nothing fixed the problem.

Do you have any idea ?