668936 has 8 divisors (see below), whose sum is σ = 1254270. Its totient is φ = 334464.

The previous prime is 668929. The next prime is 668939. The reversal of 668936 is 639866.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 504100 + 164836 = 710^2 + 406^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 668936.

It is not an unprimeable number, because it can be changed into a prime (668939) by changing a digit.

668936 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 (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41801 + ... + 41816.

2⁶⁶⁸⁹³⁶ is an apocalyptic number.

It is an amenable number.

668936 is a deficient number, since it is larger than the sum of its proper divisors (585334).

668936 is a wasteful number, since it uses less digits than its factorization.

668936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83623 (or 83619 counting only the distinct ones).

The product of its digits is 46656, while the sum is 38.

The square root of 668936 is about 817.8850775017. The cubic root of 668936 is about 87.4570564785.

The spelling of 668936 in words is "six hundred sixty-eight thousand, nine hundred thirty-six".