1. A failure predictor for predicting failure of a fixing device comprising: a first characteristics value extractor to count a number of fixed sheets to extract a first characteristics value representing a time interval between each implementation of repair of a surface of one of a pair of rotary bodies based on the number of fixed sheets thus counted; a second characteristics value extractor to extract a second characteristics value representing a change in a degree of glossiness on the surface of one of the pair of rotary bodies measured by a glossiness measuring device during a period of time between before and after repair of the surface of one of the pair of rotary bodies; a third characteristics value extractor to extract a third characteristics value representing a change in a current value of a drive motor that rotates the pair of rotary bodies; and a determination device to predict failure of the fixing device caused by the condition of the surface of one of the pair of rotary bodies using the extracted first, second, and third characteristics values.