866660 has 24 divisors (see below), whose sum is σ = 1927800. Its totient is φ = 326144.

The previous prime is 866653. The next prime is 866683. The reversal of 866660 is 66668.

It is a happy number.

866660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 379456 + 487204 = 616^2 + 698^2 .

It is a nialpdrome in base 10.

It is a congruent number.

It is an unprimeable number.

866660 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 7 ways as a sum of consecutive naturals, for example, 935 + ... + 1614.

It is an arithmetic number, because the mean of its divisors is an integer number (80325).

2⁸⁶⁶⁶⁶⁰ is an apocalyptic number.

It is an amenable number.

866660 is an abundant number, since it is smaller than the sum of its proper divisors (1061140).

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

866660 is a wasteful number, since it uses less digits than its factorization.

866660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2575 (or 2573 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 866660 is about 930.9457556700. The cubic root of 866660 is about 95.3417057323.

The spelling of 866660 in words is "eight hundred sixty-six thousand, six hundred sixty".