866944 has 32 divisors (see below), whose sum is σ = 1863540. Its totient is φ = 399360.

The previous prime is 866941. The next prime is 866953. The reversal of 866944 is 449668.

It can be written as a sum of positive squares in 2 ways, for example, as 788544 + 78400 = 888^2 + 280^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1404 + ... + 1924.

2⁸⁶⁶⁹⁴⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 866944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (931770).

866944 is an abundant number, since it is smaller than the sum of its proper divisors (996596).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

866944 is a wasteful number, since it uses less digits than its factorization.

866944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548 (or 536 counting only the distinct ones).

The product of its digits is 41472, while the sum is 37.

The square root of 866944 is about 931.0982762308. The cubic root of 866944 is about 95.3521189229.

The spelling of 866944 in words is "eight hundred sixty-six thousand, nine hundred forty-four".