Bluebulb Projects' The Measure of Things presents:
2,600 is about one-and-one-fourth times the number of Steps in the Sears Tower.
In other words, it's 1.2330 times the count of Steps in the Sears Tower, and the count of Steps in the Sears Tower is 0.8110 times that amount.
(a.k.a. Willis Tower) (Chicago, Illinois) (steps per stairwell)