668388672 has 280 divisors, whose sum is σ = 2298411456. Its totient is φ = 188116992.

The previous prime is 668388649. The next prime is 668388673. The reversal of 668388672 is 276883866.

It is a happy number.

668388672 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.

Its product of digits (4644864) is a multiple of the sum of its prime divisors (288).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668388673) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4100463 + ... + 4100625.

Almost surely, 2^668388672 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 668388672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1149205728).

668388672 is an abundant number, since it is smaller than the sum of its proper divisors (1630022784).

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

668388672 is a wasteful number, since it uses less digits than its factorization.

668388672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307 (or 288 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 54.

The square root of 668388672 is about 25853.2139588098. The cubic root of 668388672 is about 874.3319731662.

The spelling of 668388672 in words is "six hundred sixty-eight million, three hundred eighty-eight thousand, six hundred seventy-two".