Comparing the number of neighbors around HLIRGs to that around random positions. Upper panel: number distributions of deblended 250 μm galaxies around HLIRGs within 100, 200, and 400″, respectively. The black symbols and error bars are the median value and 16th/84th percentiles calculated from 100 realizations of random galaxies. Bottom: cumulative distribution function (CDF) of the number of HLIRG neighbors and random neighbors. HLIRGs on average have more 250 μm neighbors than random positions. This difference becomes weaker as radius increases, reducing from 3.7σ within 100″ to 2.7σ within 200″, and 1.6σ within 400″, respectively.