6661968768 has 640 divisors, whose sum is σ = 25544977920. Its totient is φ = 1675137024.

The previous prime is 6661968751. The next prime is 6661968793. The reversal of 6661968768 is 8678691666.

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 (13) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 21700071 + ... + 21700377.

It is an arithmetic number, because the mean of its divisors is an integer number (39914028).

Almost surely, 2^6661968768 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 6661968768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12772488960).

6661968768 is an abundant number, since it is smaller than the sum of its proper divisors (18883009152).

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

6661968768 is a wasteful number, since it uses less digits than its factorization.

6661968768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376 (or 355 counting only the distinct ones).

The product of its digits is 31352832, while the sum is 63.

The square root of 6661968768 is about 81620.8843862893. The cubic root of 6661968768 is about 1881.6298646863.

The spelling of 6661968768 in words is "six billion, six hundred sixty-one million, nine hundred sixty-eight thousand, seven hundred sixty-eight".