9528831721 has 16 divisors (see below), whose sum is σ = 10630872000. Its totient is φ = 8487894528.

The previous prime is 9528831647. The next prime is 9528831733. The reversal of 9528831721 is 1271388259.

It is a happy number.

9528831721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 9528831721 - 2²⁷ = 9394613993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9528835721) 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, 324766 + ... + 352888.

It is an arithmetic number, because the mean of its divisors is an integer number (664429500).

Almost surely, 2^9528831721 is an apocalyptic number.

It is an amenable number.

9528831721 is a deficient number, since it is larger than the sum of its proper divisors (1102040279).

9528831721 is a wasteful number, since it uses less digits than its factorization.

9528831721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29208.

The product of its digits is 241920, while the sum is 46.

The square root of 9528831721 is about 97615.7350072210. The cubic root of 9528831721 is about 2120.0521911472.

The spelling of 9528831721 in words is "nine billion, five hundred twenty-eight million, eight hundred thirty-one thousand, seven hundred twenty-one".