866858 has 4 divisors (see below), whose sum is σ = 1300290. Its totient is φ = 433428.

The previous prime is 866857. The next prime is 866869. The reversal of 866858 is 858668.

866858 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.

It can be written as a sum of positive squares in only one way, i.e., 786769 + 80089 = 887^2 + 283^2 .

It is not an unprimeable number, because it can be changed into a prime (866851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 216713 + ... + 216716.

2⁸⁶⁶⁸⁵⁸ is an apocalyptic number.

866858 is a deficient number, since it is larger than the sum of its proper divisors (433432).

866858 is a wasteful number, since it uses less digits than its factorization.

866858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433431.

The product of its digits is 92160, while the sum is 41.

The square root of 866858 is about 931.0520930646. The cubic root of 866858 is about 95.3489658729.

It can be divided in two parts, 8 and 66858, that added together give a palindrome (66866).

The spelling of 866858 in words is "eight hundred sixty-six thousand, eight hundred fifty-eight".