The bank, which remains 62% owned by the taxpayer following its bailout at the height of the financial crisis, reported a pre-tax profit of £1.6bn for 2018 - up from £752m in the previous 12 months.
But it also used its results to warn that economic challenges, including from Brexit, risked knocking its cost-cutting targets, demands for loans and raising its exposure to potential loan defaults.
While it did not raise its provision for Brexit-related costs above the £100m already announced last year, the bank's chief executive told Sky News it was starting to see a fall in demand for credit.
RBS said its underlying performance allowed it to pay a special dividend on top of the ordinary award which, when measured against the Treasury's stake, meant £977m would return to the public purse.
RBS is hoping the process of returning to private hands can be stepped up but its shares, at just over 240p a share, remain well below the 502p paid back in 2008 by the-then Labour government.
It was able to resume dividends last summer - for the first time since its rescue - after agreeing with US authorities a penalty of £3.7bn for the mis-selling of pre-crisis mortgage-backed securities.
The bank reported further progress in its financial recovery during 2018 and said it was stepping up efforts to bolster customer service through a £1bn investment this year.
Its chief executive said its results were achieved against the backdrop of the economic slowdown and continued fog shrouding the outcome of Brexit.
"It's mainly the large corporates that are sitting back from investing at the moment... that then tends to have second ranking effects into other smaller businesses," he said.
He added: We do need to get on and get a negotiation done so we bring certainty and this economy doesn't slow down badly."
Mr McEwan had earlier told investors: "With (Other OTC: WWTH - news) strong capital and liquidity levels, we are well positioned to support the UK economy. Our total lending to business and commercial customers reached over £100bn at the end of 2018."
The bank's annual report also confirmed a story by Sky News last weekend that it awarded £335m in bonuses to staff for the year - a fall on the £342m handed out in 2017.
Mr McEwan's pay package rose to £3.6m from £3.5m.
RBS achieved cost-savings of £278m in costs but conduct and litigation charges of £1.3bn were added.
They included an extra provision of £50m for costs associated with its controversial former turnaround unit, the Global Restructuring Group.
The bank is battling numerous former business clients who accuse it of pushing them into bankruptcy in order to secure lucrative fees and, in some cases, control of their companies.
Neil Wilson, chief market analyst at Markets.com, said: "RBS delivered a stellar set of numbers and a forecast-beating dividend payout to investors, but Brexit and other factors mean it will fall short on its cost cutting target."