668831 has 4 divisors (see below), whose sum is σ = 708192. Its totient is φ = 629472.

The previous prime is 668821. The next prime is 668851. The reversal of 668831 is 138866.

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 668831 - 2¹⁴ = 652447 is a prime.

It is a super-2 number, since 2×668831² = 894669813122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668821) by changing a digit.

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, 19655 + ... + 19688.

It is an arithmetic number, because the mean of its divisors is an integer number (177048).

2⁶⁶⁸⁸³¹ is an apocalyptic number.

668831 is a deficient number, since it is larger than the sum of its proper divisors (39361).

668831 is a wasteful number, since it uses less digits than its factorization.

668831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39360.

The product of its digits is 6912, while the sum is 32.

The square root of 668831 is about 817.8208850353. The cubic root of 668831 is about 87.4524803200.

The spelling of 668831 in words is "six hundred sixty-eight thousand, eight hundred thirty-one".