Hexadecimal to Decimal

Can anyone help??? I know excel is limited to 10 digits when converting using =Hex2dec(H2) so I thought =HEX2DEC(LEFT(H2,7))*16^7+HEX2DEC(RIGHT(H2,7)) would work for a 14 digit number (04741E3A254F80).

And it does, other than the last digit, which should be a 2 and it's converting to a 0. (i.e. it should convert to 1253573080207232 but it converts to 1253573080207230)

Any ideas??? Thanks all!