666888768 has 224 divisors, whose sum is σ = 2413528320. Its totient is φ = 175841280.

The previous prime is 666888731. The next prime is 666888791. The reversal of 666888768 is 867888666.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (63).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 155128 + ... + 159368.

It is an arithmetic number, because the mean of its divisors is an integer number (10774680).

Almost surely, 2^666888768 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 666888768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1206764160).

666888768 is an abundant number, since it is smaller than the sum of its proper divisors (1746639552).

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

666888768 is a wasteful number, since it uses less digits than its factorization.

666888768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4282 (or 4266 counting only the distinct ones).

The product of its digits is 37158912, while the sum is 63.

The square root of 666888768 is about 25824.1895903821. The cubic root of 666888768 is about 873.6774656581.

The spelling of 666888768 in words is "six hundred sixty-six million, eight hundred eighty-eight thousand, seven hundred sixty-eight".