Samsung MX Division (which makes smartphones, tablets, computers, wearables and network equipment) only had $19 billion. For anyone who thinks Galaxy smartphones are anywhere close to the iPhone for sales.
The corporate comparisons you made are valid, but be careful comparing to Samsung divisions. Samsung phones use Samsung components and it's not clear what division is credited with the profit for those components. So when Samsung puts their own RAM and flash components in their phone, does the Mobile division get the parts at cost at the expense of the Semiconductor group, or does Semiconductors get to charge Mobile whatever markup they want?
It's possible Samsung sells RAM to itself at a higher margin than other customers in order to show better profitability in Semiconductors. I don't know what they do for sure, but I always try to keep that in mind when I compare against a division of a conglomerate like that.