866999 has 8 divisors (see below), whose sum is σ = 997248. Its totient is φ = 738360.

The previous prime is 866969. The next prime is 867001. The reversal of 866999 is 999668.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 866999 - 2⁸ = 866743 is a prime.

866999 is a modest number, since divided by 999 gives 866 as remainder.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 866999.

It is not an unprimeable number, because it can be changed into a prime (866909) 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, 1184 + ... + 1770.

It is an arithmetic number, because the mean of its divisors is an integer number (124656).

2⁸⁶⁶⁹⁹⁹ is an apocalyptic number.

866999 is a deficient number, since it is larger than the sum of its proper divisors (130249).

866999 is a wasteful number, since it uses less digits than its factorization.

866999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 805.

The product of its digits is 209952, while the sum is 47.

The square root of 866999 is about 931.1278107757. The cubic root of 866999 is about 95.3541352990.

The spelling of 866999 in words is "eight hundred sixty-six thousand, nine hundred ninety-nine".