668766 has 16 divisors (see below), whose sum is σ = 1528704. Its totient is φ = 191064.

The previous prime is 668761. The next prime is 668791. The reversal of 668766 is 667866.

668766 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668761) by changing a digit.

668766 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, 7920 + ... + 8003.

It is an arithmetic number, because the mean of its divisors is an integer number (95544).

2⁶⁶⁸⁷⁶⁶ is an apocalyptic number.

668766 is an abundant number, since it is smaller than the sum of its proper divisors (859938).

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

668766 is a wasteful number, since it uses less digits than its factorization.

668766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15935.

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

The square root of 668766 is about 817.7811443167. The cubic root of 668766 is about 87.4496472200.

Subtracting from 668766 its reverse (667866), we obtain a square (900 = 30²).

The spelling of 668766 in words is "six hundred sixty-eight thousand, seven hundred sixty-six".