6643441728 has 336 divisors, whose sum is σ = 24253691904. Its totient is φ = 1688325120.

The previous prime is 6643441711. The next prime is 6643441729. The reversal of 6643441728 is 8271443466.

It is a tau number, because it is divible by the number of its divisors (336).

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

It is not an unprimeable number, because it can be changed into a prime (6643441729) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2082951 + ... + 2086137.

Almost surely, 2^6643441728 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 6643441728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12126845952).

6643441728 is an abundant number, since it is smaller than the sum of its proper divisors (17610250176).

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

6643441728 is a wasteful number, since it uses less digits than its factorization.

6643441728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3270 (or 3257 counting only the distinct ones).

The product of its digits is 774144, while the sum is 45.

The square root of 6643441728 is about 81507.3108868155. The cubic root of 6643441728 is about 1879.8839644695.

The spelling of 6643441728 in words is "six billion, six hundred forty-three million, four hundred forty-one thousand, seven hundred twenty-eight".