728861 has 4 divisors (see below), whose sum is σ = 832992. Its totient is φ = 624732.

The previous prime is 728851. The next prime is 728867. The reversal of 728861 is 168827.

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, and also an emirpimes, since its reverse is a distinct semiprime: 168827 = 17 ⋅9931.

It is a cyclic number.

It is not a de Polignac number, because 728861 - 2¹⁴ = 712477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728867) 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, 52055 + ... + 52068.

It is an arithmetic number, because the mean of its divisors is an integer number (208248).

2⁷²⁸⁸⁶¹ is an apocalyptic number.

It is an amenable number.

728861 is a deficient number, since it is larger than the sum of its proper divisors (104131).

728861 is a wasteful number, since it uses less digits than its factorization.

728861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104130.

The product of its digits is 5376, while the sum is 32.

The square root of 728861 is about 853.7335649955. The cubic root of 728861 is about 89.9942794718.

The spelling of 728861 in words is "seven hundred twenty-eight thousand, eight hundred sixty-one".