NL25 Weird River Spot with AK

my hand here is pretty face up I think and as such may induce more bluffing but im not sure, is this a super easy fold and I'm just overthinking it?
Submitted by : ReSpOnSe

PokerStars Game #18527098933: Hold'em No Limit ($0.10/$0.25) - 2008/07/02 - 08:33:16 (ET)
Table 'Polydoros' 6-max Seat #3 is the button
Seat 2: NeOReSpOnSe ($25.60 in chips)
Seat 3: SickBlindPS ($24.60 in chips)
Seat 4: AnssiJuhani ($28.05 in chips)
Seat 5: ArunSh ($15.50 in chips)
Seat 6: attase ($44.15 in chips)
AnssiJuhani: posts small blind $0.10
ArunSh: posts big blind $0.25

Holecards
Dealt to NeOReSpOnSe
attase: folds
NeOReSpOnSe : raises $0.75 to $1
SickBlindPS: calls $1
AnssiJuhani: folds
ArunSh: calls $0.75

Flop (Pot : $3.10)

   
ArunSh: checks
NeOReSpOnSe : checks
Sailermoon89 joins the table at seat #1
SickBlindPS: checks

Turn (Pot : $3.10)

   
ArunSh: checks
NeOReSpOnSe : bets $2.25
SickBlindPS: calls $2.25
ArunSh: folds

River (Pot : $7.60)

   
NeOReSpOnSe : bets $5.25
SickBlindPS: raises $16.10 to $21.35 and is all-in
NeOReSpOnSe : ?

Is this pretty much always a flopped set river full house(or some weird straight)? could something like AQ or AJ do this too? and there are no results because i folded:-P

easy fold
AJ and AQ will be happy to call ,unless vilain is hyperagroDonk overplaying TPGK but I doubt it