866686 has 16 divisors (see below), whose sum is σ = 1378944. Its totient is φ = 407704.

The previous prime is 866683. The next prime is 866689. The reversal of 866686 is 686668.

It is an interprime number because it is at equal distance from previous prime (866683) and next prime (866689).

It is a super-2 number, since 2×866686² = 1502289245192, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3705 + ... + 3931.

It is an arithmetic number, because the mean of its divisors is an integer number (86184).

2⁸⁶⁶⁶⁸⁶ is an apocalyptic number.

866686 is a deficient number, since it is larger than the sum of its proper divisors (512258).

866686 is a wasteful number, since it uses less digits than its factorization.

866686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335.

The product of its digits is 82944, while the sum is 40.

The square root of 866686 is about 930.9597198590. The cubic root of 866686 is about 95.3426591471.

The spelling of 866686 in words is "eight hundred sixty-six thousand, six hundred eighty-six".