In this paper, our aim is to find the radii of starlikeness and convexity of the Ramanujan type function for three different kinds of normalization by using their Mittag–Leffler expansion in such a way that the resulting functions are analytic in the unit disk of the complex plane. A result of Zhang (Proc Am Math Soc 145:241–250, 2017) on the reality of the zeros of Ramanujan type entire functions play important roles in this paper. Moreover, the interlacing properties of the zeros of Ramanujan type functions and its derivative are also useful in the proof of the main results. In addition, by using the Euler–Rayleigh inequalities, we obtain some tight lower and upper bounds for the radii of starlikeness and convexity of order zero for the Ramanujan type entire functions. Finally, we give monotonicity and Redheffer-type inequalities for this function.

在本文中，我们的目的是通过使用Mittag-Leffler展开法来找到三种不同规格化的Ramanujan型函数的星形半径和凸半径，以使所得函数在复数的单位圆盘中进行分析。飞机。Zhang（Proc Am Math Soc 145：241–250，2017）关于Ramanujan类型零点的现实的结果在本文中起着重要作用。此外，Ramanujan类型函数的零点的交织特性及其导数也可用于证明主要结果。另外，通过使用Euler-Rayleigh不等式，我们获得了Ramanujan型整个函数的星形半径和零级凸半径的紧密上下限。最后，