668238816 has 192 divisors, whose sum is σ = 2128896000. Its totient is φ = 179283456.

The previous prime is 668238811. The next prime is 668238829. The reversal of 668238816 is 618832866.

It is a Harshad number since it is a multiple of its sum of digits (48).

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 (668238811) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2540701 + ... + 2540963.

It is an arithmetic number, because the mean of its divisors is an integer number (11088000).

Almost surely, 2^668238816 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 668238816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1064448000).

668238816 is an abundant number, since it is smaller than the sum of its proper divisors (1460657184).

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

668238816 is a wasteful number, since it uses less digits than its factorization.

668238816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 501 (or 493 counting only the distinct ones).

The product of its digits is 663552, while the sum is 48.

The square root of 668238816 is about 25850.3155880156. The cubic root of 668238816 is about 874.2666251180.

The spelling of 668238816 in words is "six hundred sixty-eight million, two hundred thirty-eight thousand, eight hundred sixteen".