A double flow turbojet includes a fan including a disk centered on an axis of the fan which is provided with fan blades on its periphery, the blades having a leading edge, and an air inlet sleeve extending upstream of the fan and configured to delimit a gas flow designed to enter into the fan the air inlet sleeve having a collecting surface, the turbojet having an aspect ratio S 2 S col included in the interval [ 1.0 ; 1.0 + 0.4 ⁢ ( L D ) ] , where L/D is the form factor of the air inlet sleeve.