Angular Date Pipe works with number value too,
But please note: Only with milliseconds.
If you want to get mm:ss(00:00)
you need to convert your number value to milliseconds. In your case it should be: 3600 * 1000
<div class="time-box" *ngIf="p.value.playerTimer > 0">
{{ p.value.playerTimer * 1000 | date:'mm:ss' }}
</div>
here is the Stackblitz example
https://stackblitz.com/edit/date-pipe-example-nhafvx
maybe someone will come in handy