668906 has 8 divisors (see below), whose sum is σ = 1146720. Its totient is φ = 286668.

The previous prime is 668903. The next prime is 668929. The reversal of 668906 is 609866.

668906 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (668903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23876 + ... + 23903.

It is an arithmetic number, because the mean of its divisors is an integer number (143340).

2⁶⁶⁸⁹⁰⁶ is an apocalyptic number.

668906 is a deficient number, since it is larger than the sum of its proper divisors (477814).

668906 is a wasteful number, since it uses less digits than its factorization.

668906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47788.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 668906 is about 817.8667373112. The cubic root of 668906 is about 87.4557490535.

The spelling of 668906 in words is "six hundred sixty-eight thousand, nine hundred six".