866831 has 4 divisors (see below), whose sum is σ = 990672. Its totient is φ = 742992.

The previous prime is 866819. The next prime is 866843. The reversal of 866831 is 138668.

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

It is an interprime number because it is at equal distance from previous prime (866819) and next prime (866843).

It is a cyclic number.

It is not a de Polignac number, because 866831 - 2¹⁰ = 865807 is a prime.

It is a super-2 number, since 2×866831² = 1502791965122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

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

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61910 + ... + 61923.

It is an arithmetic number, because the mean of its divisors is an integer number (247668).

2⁸⁶⁶⁸³¹ is an apocalyptic number.

866831 is a deficient number, since it is larger than the sum of its proper divisors (123841).

866831 is a wasteful number, since it uses less digits than its factorization.

866831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123840.

The product of its digits is 6912, while the sum is 32.

The square root of 866831 is about 931.0375932260. The cubic root of 866831 is about 95.3479759188.

The spelling of 866831 in words is "eight hundred sixty-six thousand, eight hundred thirty-one".