in Pickup_Powerup
	if ( !other->client->ps.powerups[ent->item->giTag] ) {
		// round timing to seconds to make multiple powerup timers
		// count in sync
		other->client->ps.powerups[ent->item->giTag] = 
			level.time - ( level.time % 1000 );
	}
...
	other->client->ps.powerups[ent->item->giTag] += quantity * 1000;

in ClientEndFrame:
	// turn off any expired powerups
	for ( i = 0 ; i < MAX_POWERUPS ; i++ ) {
		if ( ent->client->ps.powerups[ i ] < level.time ) {
			ent->client->ps.powerups[ i ] = 0;
		}
	}

if you don't currently have the powerup and quantity(count) is 2147483 then getting
the powerup in the first second sets it to:
	level.time - (level.time % 1000) + quantity * 1000
	= 0 + 2147483000
	= 2147483000

in the second second:
	level.time - (level.time % 1000) + quantity * 1000
	= 1000 + 2147483000
	= 2147484000
	= -2147483296

and so it will be turned off because -2147483296 < level.time
the same thing will happen until level.time >= 2147485000
so the powerup will not be usable for around 24 days

sometimes in defrag setting count to 2147483 doesn't work (the powerup can
never be picked up). 2147482 seems to work and of course lower values can be
used to make the powerup usable for a longer amount of time.