866680 has 32 divisors (see below), whose sum is σ = 1995840. Its totient is φ = 338560.

The previous prime is 866653. The next prime is 866683. The reversal of 866680 is 86668.

It is a happy number.

It is a super-2 number, since 2×866680² = 1502268444800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866683) by changing a digit.

866680 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 7 ways as a sum of consecutive naturals, for example, 1650 + ... + 2110.

It is an arithmetic number, because the mean of its divisors is an integer number (62370).

2⁸⁶⁶⁶⁸⁰ 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 866680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (997920).

866680 is an abundant number, since it is smaller than the sum of its proper divisors (1129160).

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

866680 is a wasteful number, since it uses less digits than its factorization.

866680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519 (or 515 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 866680 is about 930.9564973725. The cubic root of 866680 is about 95.3424391300.

The spelling of 866680 in words is "eight hundred sixty-six thousand, six hundred eighty".