866404 has 48 divisors (see below), whose sum is σ = 1975680. Its totient is φ = 322560.

The previous prime is 866399. The next prime is 866417. The reversal of 866404 is 404668.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8884 + ... + 8980.

It is an arithmetic number, because the mean of its divisors is an integer number (41160).

2⁸⁶⁶⁴⁰⁴ 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 866404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (987840).

866404 is an abundant number, since it is smaller than the sum of its proper divisors (1109276).

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

866404 is a wasteful number, since it uses less digits than its factorization.

866404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 866404 is about 930.8082509303. The cubic root of 866404 is about 95.3323172446.

The spelling of 866404 in words is "eight hundred sixty-six thousand, four hundred four".