9688721 has 16 divisors (see below), whose sum is σ = 11558400. Its totient is φ = 8114400.

The previous prime is 9688711. The next prime is 9688739. The reversal of 9688721 is 1278869.

9688721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9688721 - 2¹⁰ = 9687697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9688711) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15821 + ... + 16421.

It is an arithmetic number, because the mean of its divisors is an integer number (722400).

Almost surely, 2^9688721 is an apocalyptic number.

It is an amenable number.

9688721 is a deficient number, since it is larger than the sum of its proper divisors (1869679).

9688721 is an equidigital number, since it uses as much as digits as its factorization.

9688721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 669 (or 655 counting only the distinct ones).

The product of its digits is 48384, while the sum is 41.

The square root of 9688721 is about 3112.6710394772. The cubic root of 9688721 is about 213.1844303264.

The spelling of 9688721 in words is "nine million, six hundred eighty-eight thousand, seven hundred twenty-one".