728838009 has 9 divisors (see below), whose sum is σ = 1052883013. Its totient is φ = 485838012.

The previous prime is 728838001. The next prime is 728838031. The reversal of 728838009 is 900838827.

The square root of 728838009 is 26997.

It is a perfect power (a square), and thus also a powerful number.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 728838009 - 2³ = 728838001 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (728838001) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 76492 + ... + 85490.

Almost surely, 2^728838009 is an apocalyptic number.

728838009 is the 26997-th square number.

728838009 is the 13499-th centered octagonal number.

It is an amenable number.

728838009 is a deficient number, since it is larger than the sum of its proper divisors (324045004).

728838009 is an frugal number, since it uses more digits than its factorization.

728838009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18004 (or 9002 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The cubic root of 728838009 is about 899.9333320987.

The spelling of 728838009 in words is "seven hundred twenty-eight million, eight hundred thirty-eight thousand, nine".