An individual seeks recommendations for an introductory number theory book suitable for high school self-study, expressing a preference for written material over video lectures. They have a foundational understanding of high school algebra, geometry, and basic linear algebra and trigonometry. Key topics of interest include congruences, primes, multiplicative functions, divisibility, and Euler's theorem. Suggestions include Dr. Keith Devlin's free online course and accompanying textbook, but the individual prefers a book that allows for more immediate engagement with number theory concepts. Pinter's "A Book on Abstract Algebra" is recommended for its clear writing and coverage of relevant topics, though it requires substantial reading before reaching number theory. Additional resources include free online pages and a book by Dudley, which is noted for its accessibility. The individual expresses gratitude for the recommendations and plans to pursue Dudley's book.