Let d(n; r 1 , q 1 , r 2 , q 2 ) be the number of factorization n = n 1 n 2 satisfying n i ≡ r i (mod q i ) (i = 1, 2) and ∆(x; r 1 , q 1 , r 2 , q 2 ) be the error term of the summatory function of d(n; r 1 , q 1 , r 2 , q 2 ) with x ≥ (q 1 q 2 ) 1+ε , 1 ≤ r i ≤ q i , and (r i , q i ) = 1 (i = 1, 2). We study the power moments and sign changes of ∆(x; r 1 , q 1 , r 2 , q 2 ), and prove that for a sufficiently large constant C, ∆(q 1 q 2 x; r 1 , q 1 , r 2 , q 2 ) changes sign in the interval [T, T + C √ T ] for any large T . Meanwhile, we show that for a small constant c ′ , there exist infinitely many subintervals of length c ′ √ T log −7 T in [T, 2T ] where ±∆(q 1 q 2 x; r 1 , q 1 , r 2 , q 2 ) > c 5 x 1 4 always holds.