866388 has 48 divisors (see below), whose sum is σ = 2225664. Its totient is φ = 261120.

The previous prime is 866353. The next prime is 866389. The reversal of 866388 is 883668.

Its product of digits (55296) is a multiple of the sum of its prime factors (192).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866389) by changing a digit.

866388 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 15 ways as a sum of consecutive naturals, for example, 6256 + ... + 6392.

It is an arithmetic number, because the mean of its divisors is an integer number (46368).

2⁸⁶⁶³⁸⁸ 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 866388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1112832).

866388 is an abundant number, since it is smaller than the sum of its proper divisors (1359276).

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

866388 is a wasteful number, since it uses less digits than its factorization.

866388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192 (or 190 counting only the distinct ones).

The product of its digits is 55296, while the sum is 39.

The square root of 866388 is about 930.7996562096. The cubic root of 866388 is about 95.3317304027.

The spelling of 866388 in words is "eight hundred sixty-six thousand, three hundred eighty-eight".