668168 has 20 divisors (see below), whose sum is σ = 1331115. Its totient is φ = 314432.

The previous prime is 668159. The next prime is 668179. The reversal of 668168 is 861866.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 3 ways, for example, as 643204 + 24964 = 802^2 + 158^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=578.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 4 ways as a sum of consecutive naturals, for example, 39296 + ... + 39312.

2⁶⁶⁸¹⁶⁸ is an apocalyptic number.

668168 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

668168 is a deficient number, since it is larger than the sum of its proper divisors (662947).

668168 is an frugal number, since it uses more digits than its factorization.

668168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74 (or 19 counting only the distinct ones).

The product of its digits is 13824, while the sum is 35.

The square root of 668168 is about 817.4154390516. The cubic root of 668168 is about 87.4235740824.

The spelling of 668168 in words is "six hundred sixty-eight thousand, one hundred sixty-eight".