866624 has 28 divisors (see below), whose sum is σ = 1877568. Its totient is φ = 393600.

The previous prime is 866623. The next prime is 866629. The reversal of 866624 is 426668.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866623) 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, 89 + ... + 1319.

It is an arithmetic number, because the mean of its divisors is an integer number (67056).

2⁸⁶⁶⁶²⁴ 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 866624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (938784).

866624 is an abundant number, since it is smaller than the sum of its proper divisors (1010944).

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

866624 is a wasteful number, since it uses less digits than its factorization.

866624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1254 (or 1244 counting only the distinct ones).

The product of its digits is 13824, while the sum is 32.

The square root of 866624 is about 930.9264202932. The cubic root of 866624 is about 95.3403855879.

The spelling of 866624 in words is "eight hundred sixty-six thousand, six hundred twenty-four".