668785 has 8 divisors (see below), whose sum is σ = 864360. Its totient is φ = 493824.

The previous prime is 668761. The next prime is 668791. The reversal of 668785 is 587866.

668785 is nontrivially palindromic in base 7.

It can be written as a sum of positive squares in 4 ways, for example, as 78961 + 589824 = 281^2 + 768^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 668785 - 2⁹ = 668273 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5080 + ... + 5209.

It is an arithmetic number, because the mean of its divisors is an integer number (108045).

2⁶⁶⁸⁷⁸⁵ is an apocalyptic number.

668785 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

668785 is a deficient number, since it is larger than the sum of its proper divisors (195575).

668785 is a wasteful number, since it uses less digits than its factorization.

668785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10307.

The product of its digits is 80640, while the sum is 40.

The square root of 668785 is about 817.7927610342. The cubic root of 668785 is about 87.4504753759.

The spelling of 668785 in words is "six hundred sixty-eight thousand, seven hundred eighty-five".