866400 has 108 divisors (see below), whose sum is σ = 2976372. Its totient is φ = 218880.

The previous prime is 866399. The next prime is 866417. The reversal of 866400 is 4668.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an Ulam number.

It is a nialpdrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 45591 + ... + 45609.

It is an arithmetic number, because the mean of its divisors is an integer number (27559).

2⁸⁶⁶⁴⁰⁰ is an apocalyptic number.

866400 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 866400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1488186).

866400 is an abundant number, since it is smaller than the sum of its proper divisors (2109972).

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

866400 is a wasteful number, since it uses less digits than its factorization.

866400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61 (or 29 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 866400 is about 930.8061022576. The cubic root of 866400 is about 95.3321705348.

Multiplying 866400 by its sum of digits (24), we get a square (20793600 = 4560²).

866400 divided by its sum of digits (24) gives a square (36100 = 190²).

The spelling of 866400 in words is "eight hundred sixty-six thousand, four hundred".