728885 has 4 divisors (see below), whose sum is σ = 874668. Its totient is φ = 583104.

The previous prime is 728881. The next prime is 728891. The reversal of 728885 is 588827.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 142129 + 586756 = 377^2 + 766^2 .

It is a cyclic number.

It is not a de Polignac number, because 728885 - 2² = 728881 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728881) 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, 72884 + ... + 72893.

It is an arithmetic number, because the mean of its divisors is an integer number (218667).

2⁷²⁸⁸⁸⁵ is an apocalyptic number.

It is an amenable number.

728885 is a deficient number, since it is larger than the sum of its proper divisors (145783).

728885 is a wasteful number, since it uses less digits than its factorization.

728885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145782.

The product of its digits is 35840, while the sum is 38.

The square root of 728885 is about 853.7476207873. The cubic root of 728885 is about 89.9952672408.

The spelling of 728885 in words is "seven hundred twenty-eight thousand, eight hundred eighty-five".