668918 has 8 divisors (see below), whose sum is σ = 1035840. Its totient is φ = 323640.

The previous prime is 668903. The next prime is 668929. The reversal of 668918 is 819866.

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

It is an Ulam number.

It is a plaindrome in base 14.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5333 + ... + 5456.

It is an arithmetic number, because the mean of its divisors is an integer number (129480).

2⁶⁶⁸⁹¹⁸ is an apocalyptic number.

668918 is a deficient number, since it is larger than the sum of its proper divisors (366922).

668918 is a wasteful number, since it uses less digits than its factorization.

668918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10822.

The product of its digits is 20736, while the sum is 38.

The square root of 668918 is about 817.8740734367. The cubic root of 668918 is about 87.4562720282.

The spelling of 668918 in words is "six hundred sixty-eight thousand, nine hundred eighteen".