Sorry, it is me again!
[74:27] What retribution!
[74:28] Thorough and comprehensive.
[74:29] Obvious to all the people.
[74:30] Over it is nineteen.
[74:31] We appointed angels to be guardians of Hell, and we assigned their number (19)
From this translation, if taken literally, then there are 19 angels that are guardians of hell. There is no other explanation since the 19 has been assigned to the number of angels.
The 19 is a trial for those who are bent upon denying the truth, so instead of trying to re-engineer the Quran to fit a 19 non-existent numerology system, pick up the Good Book, learn a thing or two about your role in the scheme of things, and do some good deeds. This will get you into Jannah; a code 19 will only unlock the gates of hell.
74:31 We have appointed none but angelic powers (Universal Laws) to be the keepers of the Fire. And We have made their number a trial for those who are bent upon denying the truth. This admonition should grant certainty to those who received the Scripture before while the believers shall increase in faith. The believers and those who have been given the Scripture before shall harbor no doubt to this declaration. And the hypocrites and the deniers may say, “What does God mean by this parable?” Thus, God lets go astray him who wills to go astray, and guides him who wills to be guided. And no one knows the Forces of your Lord but He. And this is nothing but a Reminder to the mortals. [2:26]