This is a famous USA telephone number that was both the subject and the title of a rock song in 1982. The full name of the song is '867-5309/Jenny' by Tommy Tutone.
Interestingly enough, it is an actual telephone number located somewhere in the state of Pennsylvania. Supposedly, every time the song plays on MTV or VH-11, the poor residents are besieged with phone calls from people curious as to whether this is an actual number or not.
The release of this song was not the incident that first prompted television and movie producers to use only false telephone numbers in their products to avoid legal liability. These numbers all begin with 555, which is not a sequence used in the USA for phone numbers.
Do not call this number. Leave the poor people who live there alone.