668426688 has 112 divisors (see below), whose sum is σ = 2068576000. Its totient is φ = 211071744.

The previous prime is 668426687. The next prime is 668426729. The reversal of 668426688 is 886624866.

It is a happy number.

668426688 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668426687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22653 + ... + 43011.

Almost surely, 2^668426688 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 668426688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1034288000).

668426688 is an abundant number, since it is smaller than the sum of its proper divisors (1400149312).

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

668426688 is a wasteful number, since it uses less digits than its factorization.

668426688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20399 (or 20383 counting only the distinct ones).

The product of its digits is 5308416, while the sum is 54.

The square root of 668426688 is about 25853.9491760930. The cubic root of 668426688 is about 874.3485493368.

The spelling of 668426688 in words is "six hundred sixty-eight million, four hundred twenty-six thousand, six hundred eighty-eight".