Narrated 'Abdullah bin 'Umar (RA):

Allah's Messenger (ﷺ) said: "The prayer offered in congregation is twenty-seven degrees more rewardable than a prayer offered by a single person." [Agreed upon].

عَنْ عَبْدِ اَللَّهِ بْنِ عُمَرَ ‏-رَضِيَ اَللَّهُ عَنْهُمَا‏-; أَنَّ رَسُولَ اَللَّهِ ‏- صلى الله عليه وسلم ‏-قَالَ: { صَلَاةُ اَلْجَمَاعَةِ أَفْضَلُ مِنْ صَلَاةِ اَلْفَذِّ بِسَبْعٍ وَعِشْرِينَ دَرَجَةً } مُتَّفَقٌ عَلَيْهِ .‏ [1]‏ .‏