Number theory. Arithmetic functions. Number theory -- Instructional exposition (textbooks, tutorial papers, etc.). Number theory -- Elementary number theory -- Arithmetic functions; related numbers; inversion formulas. Number theory -- Multiplicative number theory -- Distribution of primes. Number theory -- Multiplicative number theory -- Primes in progressions. Number theory -- Additive number theory; partitions -- Applications of the Hardy-Littlewood method. Number theory -- Algebraic number theory: global fields -- Zeta functions and $L$-functions of number fields. Number theory -- Algebraic number theory: global fields -- Distribution of prime ideals.