9638721 has 12 divisors (see below), whose sum is σ = 13949520. Its totient is φ = 6413400.

The previous prime is 9638659. The next prime is 9638743. The reversal of 9638721 is 1278369.

It is not a de Polignac number, because 9638721 - 2¹⁰ = 9637697 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (9638021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8646 + ... + 9696.

It is an arithmetic number, because the mean of its divisors is an integer number (1162460).

Almost surely, 2^9638721 is an apocalyptic number.

It is an amenable number.

9638721 is a deficient number, since it is larger than the sum of its proper divisors (4310799).

9638721 is a wasteful number, since it uses less digits than its factorization.

9638721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2076 (or 2073 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 9638721 is about 3104.6289633385. The cubic root of 9638721 is about 212.8170749791.

The spelling of 9638721 in words is "nine million, six hundred thirty-eight thousand, seven hundred twenty-one".