866646 has 32 divisors (see below), whose sum is σ = 2102400. Its totient is φ = 262440.

The previous prime is 866641. The next prime is 866653. The reversal of 866646 is 646668.

It is a self number, because there is not a number n which added to its sum of digits gives 866646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 136 + ... + 1323.

It is an arithmetic number, because the mean of its divisors is an integer number (65700).

2⁸⁶⁶⁶⁴⁶ is an apocalyptic number.

866646 is an abundant number, since it is smaller than the sum of its proper divisors (1235754).

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

866646 is a wasteful number, since it uses less digits than its factorization.

866646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1481 (or 1475 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 866646 is about 930.9382364045. The cubic root of 866646 is about 95.3411923471.

The spelling of 866646 in words is "eight hundred sixty-six thousand, six hundred forty-six".