So the smallest such number is 1001, but it is not three-digit.

Fri, 17 Apr 2026 17:24:08 +0000

Why 1001 Is the Smallest Three-Digit Number Beginning with 1001—and Why It’s Not Really Three-Digit in the Way You Think When considering the smallest three-digit number that starts with the digits “100,” most people automatically settle on 100 as the lowest. But wait—what about 1001? It’s larger, yes, but lies somewhere in the crossover between three- and four-digit numbers. So is 1001 truly the smallest number that qualifies as a three-digit number starting with “1001”? Not exactly. ### The Confusion: Defining “Three-Digit” At first glance, “three-digit” clearly refers to numbers from 100 to 999. These strictly have exactly three digits—no more, no less. In this range, 100 is the smallest and the only number beginning with “100.” Numbers like 101, 102, up to 999 follow, but nothing satisfies the initial “1001” pattern while staying three digits.