666860 has 12 divisors (see below), whose sum is σ = 1400448. Its totient is φ = 266736.

The previous prime is 666857. The next prime is 666871. The reversal of 666860 is 68666.

It is a happy number.

666860 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16652 + ... + 16691.

It is an arithmetic number, because the mean of its divisors is an integer number (116704).

2⁶⁶⁶⁸⁶⁰ is an apocalyptic number.

It is an amenable number.

666860 is an abundant number, since it is smaller than the sum of its proper divisors (733588).

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

666860 is a wasteful number, since it uses less digits than its factorization.

666860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33352 (or 33350 counting only the distinct ones).

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

The square root of 666860 is about 816.6149643498. The cubic root of 666860 is about 87.3664902686.

It can be divided in two parts, 6 and 66860, that added together give a palindrome (66866).

The spelling of 666860 in words is "six hundred sixty-six thousand, eight hundred sixty".