How many letters does the top answer for “author of the double” have?

The most common answer is dostoyevsky (11 letters).

Crossword clue: author of the double

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

dostoyevsky 11 letters wd-fact-v3

Russian novelist who wrote of human suffering with humor and psychological insight (1821-1881)

author of double indemnity 67% similar → cain, wilder

author of double star 67% similar → heinlein

author of the double-bass 67% similar → suskind

author of the double helix 67% similar → watson

author of 1q84 50% similar → murakami

author of 2666 50% similar → bolano

author of 4 3 2 1 50% similar → auster

author of q11368 50% similar → kernighan, ritchie