How many letters does the top answer for “author of nixon in china” have?

The most common answer is adams (5 letters).

Crossword clue: author of nixon in china

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

adams 5 letters wd-fact-v3

a mountain peak in southwestern Washington in the Cascade Range (12,307 feet high)

author of china illustrata 50% similar → kircher

composer of nixon in china 50% similar → adams

wrote nixon in china 50% similar → adams