number twin 

Someone who has the same phone number you have except for the for the area code. [phone] and [phone]

I met this person last night and when she gave me her phone number it was the same as mine except for the city area code. We are like number twins or something!

number twin by Cot Crunch August 6, 2019

Numbertwonity 

A precious opportunity to take a “Number Two”

Oof. We’re not stopping for a while, you better take this numbertwonity cause you’ll be shit out of luck if you don’t.

Numbertwonity by Teach Ben September 3, 2021

numberthing 

noun. pl. numberthings. a mathematical object constructed of numbers, algebra, and/or operation sequences.
Numberthings are very real objects but they are completely intangible and not necessarily connected to any physical objects or phenomena.
A numberthing exists solely within one of the infinite worlds of mathematics, reason, and computing itself.

TV shows make meaningless dancing collages of numberthings appear to depict geniuses afoot or at work. When the audience tries to freeze-frame view any given numberthing in that collage, it's either a generic formula or gibberish.

numberthing by Little.Fire May 1, 2022