668911 has 4 divisors (see below), whose sum is σ = 670824. Its totient is φ = 667000.

The previous prime is 668903. The next prime is 668929. The reversal of 668911 is 119866.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 668911 - 2³ = 668903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668111) 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, 265 + ... + 1186.

It is an arithmetic number, because the mean of its divisors is an integer number (167706).

2⁶⁶⁸⁹¹¹ is an apocalyptic number.

668911 is a deficient number, since it is larger than the sum of its proper divisors (1913).

668911 is a wasteful number, since it uses less digits than its factorization.

668911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1912.

The product of its digits is 2592, while the sum is 31.

The square root of 668911 is about 817.8697940381. The cubic root of 668911 is about 87.4559669604.

The spelling of 668911 in words is "six hundred sixty-eight thousand, nine hundred eleven".