866939 has 4 divisors (see below), whose sum is σ = 904656. Its totient is φ = 829224.

The previous prime is 866933. The next prime is 866941. The reversal of 866939 is 939668.

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

It is a cyclic number.

It is not a de Polignac number, because 866939 - 2⁸ = 866683 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 866896 and 866905.

It is not an unprimeable number, because it can be changed into a prime (866933) 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 3 ways as a sum of consecutive naturals, for example, 18824 + ... + 18869.

It is an arithmetic number, because the mean of its divisors is an integer number (226164).

2⁸⁶⁶⁹³⁹ is an apocalyptic number.

866939 is a deficient number, since it is larger than the sum of its proper divisors (37717).

866939 is a wasteful number, since it uses less digits than its factorization.

866939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37716.

The product of its digits is 69984, while the sum is 41.

The square root of 866939 is about 931.0955912257. The cubic root of 866939 is about 95.3519356117.

The spelling of 866939 in words is "eight hundred sixty-six thousand, nine hundred thirty-nine".