In the Quran there is a nice challenge about changing the Quran through the time ... even changing one letter means that it has been changed ( scientifically and logically) but even that never done since 1400 years :
15:9 إِنَّا نَحْنُ نَزَّلْنَا الذِّكْرَ وَإِنَّا لَهُ لَحَافِظُونَ
We have, without doubt, sent down the Message; and We will assuredly guard it (from corruption).
Again we have new important verse here with 7 words only and 28 letters (7 x 28) to assure the Miracle of 7 and its importance in the structure of the Quran
(note: Arabic is from right to left)
if we make a number from the letters count :
Also : 62315533 ÷ 7 = 8902219
also : 62315533 ÷ 23 = 2709371 (23 years = the Revelation period of the quran)