9721231 has 8 divisors (see below), whose sum is σ = 10626224. Its totient is φ = 8838720.

The previous prime is 9721199. The next prime is 9721241. The reversal of 9721231 is 1321279.

9721231 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9721231 - 2⁵ = 9721199 is a prime.

It is a super-2 number, since 2×9721231² = 189004664310722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 9721196 and 9721205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9721241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4710 + ... + 6451.

It is an arithmetic number, because the mean of its divisors is an integer number (1328278).

Almost surely, 2^9721231 is an apocalyptic number.

9721231 is a deficient number, since it is larger than the sum of its proper divisors (904993).

9721231 is a wasteful number, since it uses less digits than its factorization.

9721231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11241.

The product of its digits is 756, while the sum is 25.

The square root of 9721231 is about 3117.8888690908. Note that the first 4 decimals coincide. The cubic root of 9721231 is about 213.4226072217.

The spelling of 9721231 in words is "nine million, seven hundred twenty-one thousand, two hundred thirty-one".