90 (عدد): الفرق بين النسختين

'''90 (تسعون)''' هو [[عدد طبيعي]] يلي العدد [[89 (عدد)|89]] ويسبق العدد [[91 (عدد)|91]].<ref>{{Cite web|url=https://oeis.org/A002827|title=Sloane's A002827 : Unitary perfect numbers|last=|first=|date=|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-29| مسار الأرشيف = http://web.archive.org/web/20170830152558/https://oeis.org/A002827 | تاريخ الأرشيف = 30 أغسطس 2017 }}</ref><ref>[http://www.sparknotes.com/testprep/books/newsat/chapter20section4.rhtml http://www.sparknotes.com/testprep/books/newsat/chapter20section4.rhtml] {{Webarchive|url=http://web.archive.org/web/20151205005525/http://www.sparknotes.com:80/testprep/books/newsat/chapter20section4.rhtml |date=05 ديسمبر 2015}}</ref><ref>{{Cite web|url=https://oeis.org/A005349|title=Sloane's A005349 : Niven (or Harshad) numbers|last=|first=|date=|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-29| مسار الأرشيف = http://web.archive.org/web/20171203175343/http://oeis.org:80/A005349 | تاريخ الأرشيف = 03 ديسمبر 2017 }}</ref>