The answer is 17 years and 6 months.
Let P=$289,416, A=$2,500, r=0.046 (4.6%), m=12 (monthly compounding) where i = r/m, and n be the time until you run out of money. Then, i=0.046/12 = 0.038333.Using the equation P = A + A{[1-(1+i)^(1-mn)]/i}, we can derive an equation for n.
Therefore, n = (1/m)*{1-[(log(1-(i*(P-A)/A)))/log(1+i)]}. This will give n = 17.516 years or approximately 17 years and 6 months.