MathDB
ASU 141 All Soviet Union MO 1970 from 11111 to 99999 in random order

Source:

June 24, 2019
number theoryDigits5-digit

Problem Statement

All the 55-digit numbers from 1111111111 to 9999999999 are written on the cards. Those cards lies in a line in an arbitrary order. Prove that the resulting 444445444445-digit number is not a power of two.