668690 has 16 divisors (see below), whose sum is σ = 1313280. Its totient is φ = 243120.

The previous prime is 668687. The next prime is 668699. The reversal of 668690 is 96866.

It is a super-2 number, since 2×668690² = 894292632200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 668690.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2930 + ... + 3149.

It is an arithmetic number, because the mean of its divisors is an integer number (82080).

2⁶⁶⁸⁶⁹⁰ is an apocalyptic number.

668690 is a deficient number, since it is larger than the sum of its proper divisors (644590).

668690 is a wasteful number, since it uses less digits than its factorization.

668690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6097.

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

The square root of 668690 is about 817.7346757965. The cubic root of 668690 is about 87.4463344395.

It can be divided in two parts, 6686 and 90, that added together give a palindrome (6776).

The spelling of 668690 in words is "six hundred sixty-eight thousand, six hundred ninety".