What do the numbers 336-7489 spell?

Answer 1

7825

Answer 2

They spell the word "density" on a phone dial.

On a standard telephone, each of the numbers from 2 to 9 have either three or four letters associated with them:

2 = ABC

3 = DEF

4 = GHI

5 = JKL

6 = MNO

7 = PQRS

8 = TUV

9 = WXYZ

So the number 336-7489 could represent a large number of possible letter combinations, but the only single common word would be DENSITY.