686766 has 16 divisors (see below), whose sum is σ = 1454544. Its totient is φ = 215424.

The previous prime is 686761. The next prime is 686773. The reversal of 686766 is 667686.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686761) by changing a digit.

686766 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, 3265 + ... + 3468.

It is an arithmetic number, because the mean of its divisors is an integer number (90909).

2⁶⁸⁶⁷⁶⁶ is an apocalyptic number.

686766 is an abundant number, since it is smaller than the sum of its proper divisors (767778).

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

686766 is a wasteful number, since it uses less digits than its factorization.

686766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6755.

The product of its digits is 72576, while the sum is 39.

The square root of 686766 is about 828.7134607330. The cubic root of 686766 is about 88.2272877964.

The spelling of 686766 in words is "six hundred eighty-six thousand, seven hundred sixty-six".