The answer to this question depends on a number of factors. Generally speaking, iPhones are generally considered to be more secure than Android phones, as iOS has a number of built-in security features and apps that are regularly updated. Android phones, on the other hand, can be vulnerable to certain types of malware and malicious apps, and their security features are not as comprehensive as those on iPhones.
However, there are steps that can be taken to make Android devices more secure. Installing a reliable antivirus app, using two-factor authentication and other security measures, enabling remote wiping of the device if it's lost or stolen, and avoiding apps from unknown sources can all help to increase the security of an Android device.