%0 Journal Article %T On factorization of operators through the spaces $l^p.$ %A Oleg I. Reinov %J Mathematics %D 2001 %I arXiv %X We give conditions on a pair of Banach spaces $X$ and $Y,$ under which each operator from $X$ to $Y,$ whose second adjoint factors compactly through the space $l^p,$ $1\le p\le+\infty$, itself compactly factors through $l^p.$ The conditions are as follows: either the space $X^*,$ or the space $Y^{***}$ possesses the Grothendieck approximation property. Leaving the corresponding question for parameters $p>1, p\neq 2,$ still open, we show that for $p=1$ the conditions are essential. %U http://arxiv.org/abs/math/0107153v1