728311409 has 4 divisors (see below), whose sum is σ = 832355904. Its totient is φ = 624266916.

The previous prime is 728311393. The next prime is 728311411. The reversal of 728311409 is 904113827.

728311409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 728311409 - 2⁴ = 728311393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (728311499) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52022237 + ... + 52022250.

It is an arithmetic number, because the mean of its divisors is an integer number (208088976).

Almost surely, 2^728311409 is an apocalyptic number.

It is an amenable number.

728311409 is a deficient number, since it is larger than the sum of its proper divisors (104044495).

728311409 is a wasteful number, since it uses less digits than its factorization.

728311409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104044494.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 728311409 is about 26987.2453021793. The cubic root of 728311409 is about 899.7165399501.

The spelling of 728311409 in words is "seven hundred twenty-eight million, three hundred eleven thousand, four hundred nine".