6643920000 has 640 divisors, whose sum is σ = 24472166400. Its totient is φ = 1589760000.

The previous prime is 6643919999. The next prime is 6643920011. The reversal of 6643920000 is 293466.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a self number, because there is not a number n which added to its sum of digits gives 6643920000.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 141359977 + ... + 141360023.

It is an arithmetic number, because the mean of its divisors is an integer number (38237760).

Almost surely, 2^6643920000 is an apocalyptic number.

6643920000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6643920000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12236083200).

6643920000 is an abundant number, since it is smaller than the sum of its proper divisors (17828246400).

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

6643920000 is a wasteful number, since it uses less digits than its factorization.

6643920000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 30.

The square root of 6643920000 is about 81510.2447548773. The cubic root of 6643920000 is about 1879.9290753385.

The spelling of 6643920000 in words is "six billion, six hundred forty-three million, nine hundred twenty thousand".