9661 is a prime number.
9661 is the lower prime of a difference of 16 between consecutive primes (A031934).
9661 has a representation as a sum of two squares; it is the sum of two consecutive squares (A027862 and A163251): 9661 = 692 + 702.
9661 is the hypotenuse of a primitive Pythagorean triple (A067756 and A140391): 96612 = 1392 + 96602.
9661 is a divisor of 2615 - 1.
Source: On-Line Encyclopedia of Integer Sequences