Used in negative, conditional, or rhetorical contexts to mean 'no matter who' or 'any person at all'. Often appears in formal or emphatic statements.
No one can deny this truth.
No one, whoever they may be, is allowed to enter this room.
この問題は、何人にも解けないだろう。
This problem probably cannot be solved by anyone.
This right cannot be violated by anyone.
誰も with a negative verb is the common way to say 'no one', whereas 何人も～ない is the more formal, literary equivalent found in legal or rhetorical writing.
何人 read なにびと means 'anyone/any person' in formal writing, while the same kanji read なんにん simply asks or states 'how many people'.
anyone; everyone; whoever · nobody; no one
Standard kanji spelling; high news frequency. Can also be read なんぴと.
Mixed kanji-kana spelling that clarifies the reading なにびと.
Formed from 何, “what” or “which,” and 人, “person,” with the native reading なにびと. It functions as an indefinite or universal expression meaning “any person” or “whoever.”