A number is called triangular if it is the sum of the first $n$ positive integers for some $n.$ For example, 10 is triangular because $10 = 1+2+3+4$ and 21 is triangular because $21 = 1+2+3+4+5+6.$ (For fun, see if you can figure out where the name "triangular" comes from.) Write a Python program to find the smallest 6-digit triangular number. Enter the smallest 6-digit triangular number as your answer below.

Guest Aug 13, 2020