9660721 has 12 divisors (see below), whose sum is σ = 11655552. Its totient is φ = 7842744.

The previous prime is 9660701. The next prime is 9660727. The reversal of 9660721 is 1270669.

It is not a de Polignac number, because 9660721 - 2⁵ = 9660689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9660727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 616 + ... + 4438.

It is an arithmetic number, because the mean of its divisors is an integer number (971296).

Almost surely, 2^9660721 is an apocalyptic number.

It is an amenable number.

9660721 is a deficient number, since it is larger than the sum of its proper divisors (1994831).

9660721 is a wasteful number, since it uses less digits than its factorization.

9660721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3868 (or 3849 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 9660721 is about 3108.1700403935. The cubic root of 9660721 is about 212.9788674693.

The spelling of 9660721 in words is "nine million, six hundred sixty thousand, seven hundred twenty-one".