The correct answer is: 1E212 (verified with a decimal to hexadecimal calculator)
To effectively convert the decimal number: 123410 to Hexadecimal (long method), you ought to convert the decimal number to binary first! After doing that, divide each 8-digit bits to 4 (example: 8888 8888 8888 8888 8888) and you will come up with: 1E212!