729128 has 8 divisors (see below), whose sum is σ = 1367130. Its totient is φ = 364560.

The previous prime is 729073. The next prime is 729139. The reversal of 729128 is 821927.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 708964 + 20164 = 842^2 + 142^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 729128.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45563 + ... + 45578.

2⁷²⁹¹²⁸ is an apocalyptic number.

It is an amenable number.

729128 is a deficient number, since it is larger than the sum of its proper divisors (638002).

729128 is a wasteful number, since it uses less digits than its factorization.

729128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91147 (or 91143 counting only the distinct ones).

The product of its digits is 2016, while the sum is 29.

The square root of 729128 is about 853.8899226481. The cubic root of 729128 is about 90.0052671814.

The spelling of 729128 in words is "seven hundred twenty-nine thousand, one hundred twenty-eight".