668608 has 28 divisors (see below), whose sum is σ = 1373632. Its totient is φ = 322560.

The previous prime is 668599. The next prime is 668609. The reversal of 668608 is 806866.

668608 = T₁₉₂ + T₁₉₃ + ... + T₂₂₂.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668609) by changing a digit.

668608 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1816 + ... + 2152.

2⁶⁶⁸⁶⁰⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (686816).

668608 is an abundant number, since it is smaller than the sum of its proper divisors (705024).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668608 is a wasteful number, since it uses less digits than its factorization.

668608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380 (or 370 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 668608 is about 817.6845357471. The cubic root of 668608 is about 87.4427598421.

The spelling of 668608 in words is "six hundred sixty-eight thousand, six hundred eight".