866728 has 16 divisors (see below), whose sum is σ = 1720980. Its totient is φ = 407808.

The previous prime is 866717. The next prime is 866737. The reversal of 866728 is 827668.

866728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 777924 + 88804 = 882^2 + 298^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3051 + ... + 3322.

2⁸⁶⁶⁷²⁸ is an apocalyptic number.

It is an amenable number.

866728 is a deficient number, since it is larger than the sum of its proper divisors (854252).

866728 is a wasteful number, since it uses less digits than its factorization.

866728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6396 (or 6392 counting only the distinct ones).

The product of its digits is 32256, while the sum is 37.

The square root of 866728 is about 930.9822769527. The cubic root of 866728 is about 95.3441992385.

Subtracting from 866728 its reverse (827668), we obtain a triangular number (39060 = T₂₇₉).

The spelling of 866728 in words is "eight hundred sixty-six thousand, seven hundred twenty-eight".