Don't have a source for the info, bu7t was told that Papayas come in male, female and hermaphroditic. The males do not have seeds. Haven't verified that, but two of my trees were seeded and one was not, and that was the explanation I got.
Hawaiian papayas grown here struggled the first winter, and di better when older. However the fruit always seemed to ripen in late winter or early spring when there was little heat, and were always rather tasteless. Suspect they would have been much better if they had ripened in the summer.