868666 has 16 divisors (see below), whose sum is σ = 1428840. Its totient is φ = 394240.

The previous prime is 868663. The next prime is 868669. The reversal of 868666 is 666868.

It is an interprime number because it is at equal distance from previous prime (868663) and next prime (868669).

It can be written as a sum of positive squares in 4 ways, for example, as 731025 + 137641 = 855^2 + 371^2 .

It is not an unprimeable number, because it can be changed into a prime (868663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 546 + ... + 1426.

2⁸⁶⁸⁶⁶⁶ is an apocalyptic number.

868666 is a deficient number, since it is larger than the sum of its proper divisors (560174).

868666 is a wasteful number, since it uses less digits than its factorization.

868666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 929.

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

The square root of 868666 is about 932.0225319165. The cubic root of 868666 is about 95.4152094089.

The spelling of 868666 in words is "eight hundred sixty-eight thousand, six hundred sixty-six".