A Study of Apalutamide in Participants With Severe Hepatic Impairment Compared With Participants With Normal Hepatic Function

Inclusion Criteria: * Participants must not have hepatic encephalopathy greater than or equal to (\>=) Grade 3 (for participants with severe hepatic impairment) where the participant lacks the capacity to provide informed consent as judged by the investigator. Mild or moderate hepatic encephalopathy that would not impede informed consent in the investigator's judgment is permitted * Participants with normal hepatic function must be in good health with no clinically significant findings from medical history, physical examination, vital signs, and laboratory evaluation, unless deemed not clinically significant by the investigator * Participants with normal hepatic function must have serum creatinine within normal limits and Creatinine Clearance (CrCL) greater than (\>) 60 milliliter per minute per 1.73 meter square (mL/min/1.73 m\^2) as calculated per Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) Creatinine Equation * Participants with severe hepatic impairment must have a total Child-Pugh score of 10 to 15 inclusive, as determined by the investigator during screening and on Day -1 prior to study drug administration. Source documents to substantiate the clinical diagnosis (for example, ultrasonography, liver biopsy, liver/spleen scan, laboratory results or clinical findings), and medical history will be reviewed and signed by the investigator * Participants with severe hepatic impairment must have CrCL \>= 45 mL/min/1.73 m\^2 as calculated per CKD-EPI Creatinine Equation Exclusion Criteria: * Use of thyroid hormone replacement therapy * Participants with normal hepatic function with presence of sexual dysfunction (abnormal libido, erectile dysfunction, etc.) or any medical condition that would affect sexual function * Participants with normal hepatic function who have Hepatitis A immunoglobulin M positivity, Hepatitis B surface antigen (HBsAg) positivity, positive serology for Hepatitis B or Hepatitis C antibodies. Hepatitis B surface antibody positivity is not exclusionary if participant can provide evidence of Hepatitis B vaccination * Participants with severe hepatic impairment who have acute or exacerbating hepatitis, fluctuating or rapidly deteriorating hepatic function as indicated by widely varying or worsening of clinical and/or laboratory signs of hepatic impairment in the judgment of either the investigator or the sponsor's medical monitor * Participants with severe hepatic impairment previously diagnosed with hepatocellular carcinoma