866000 has 40 divisors (see below), whose sum is σ = 2098824. Its totient is φ = 345600.

The previous prime is 865993. The next prime is 866003. The reversal of 866000 is 668.

866000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 153664 + 712336 = 392^2 + 844^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a nialpdrome in base 10.

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 866000.

It is not an unprimeable number, because it can be changed into a prime (866003) by changing a digit.

866000 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1784 + ... + 2216.

2⁸⁶⁶⁰⁰⁰ is an apocalyptic number.

866000 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 866000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1049412).

866000 is an abundant number, since it is smaller than the sum of its proper divisors (1232824).

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

866000 is a wasteful number, since it uses less digits than its factorization.

866000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456 (or 440 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 866000 is about 930.5912099305. The cubic root of 866000 is about 95.3174972745.

Adding to 866000 its reverse (668), we get a palindrome (866668).

The spelling of 866000 in words is "eight hundred sixty-six thousand".