866817 has 12 divisors (see below), whose sum is σ = 1431040. Its totient is φ = 495288.

The previous prime is 866783. The next prime is 866819. The reversal of 866817 is 718668.

It is not a de Polignac number, because 866817 - 2⁷ = 866689 is a prime.

It is a super-2 number, since 2×866817² = 1502743422978, which contains 22 as substring.

It is a Duffinian number.

866817 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (866819) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6817 + ... + 6942.

2⁸⁶⁶⁸¹⁷ is an apocalyptic number.

It is an amenable number.

866817 is a deficient number, since it is larger than the sum of its proper divisors (564223).

866817 is a wasteful number, since it uses less digits than its factorization.

866817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13772 (or 13769 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 866817 is about 931.0300747022. The cubic root of 866817 is about 95.3474626012.

It can be divided in two parts, 86 and 6817, that added together give a triangular number (6903 = T₁₁₇).

The spelling of 866817 in words is "eight hundred sixty-six thousand, eight hundred seventeen".