JavaScript
const formatSeconds = (s) => new Date(s * 1000).toISOString().substr(11, 8)
const formatSeconds = (s) => new Date(s * 1000).toUTCString().match(/(\d\d:\d\d:\d\d)/)[0]
const formatSeconds = (s) => [parseInt(s / 60 / 60), parseInt((s / 60) % 60), parseInt(s % 60)].join(':').replace(/\b(\d)\b/g, '0$1')
TypeScript
const formatSeconds = (s: number): string => new Date(s * 1000).toISOString().substr(11, 8)\
const formatSeconds = (s: number): string => (new Date(s * 1000).toUTCString().match(/(\d\d:\d\d:\d\d)/) as string[])[0]
const formatSeconds = (s: number): string =>
[parseInt(`${s / 3600}`), parseInt(`${(s / 60) % 60}`), parseInt(`${s % 60}`)].join(':').replace(/\b(\d)\b/g, '0$1')
Examples
formatSeconds(200)
formatSeconds(500)