6643915880 has 96 divisors (see below), whose sum is σ = 17634723840. Its totient is φ = 2245783680.

The previous prime is 6643915847. The next prime is 6643915891. The reversal of 6643915880 is 885193466.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 115289 + ... + 163031.

It is an arithmetic number, because the mean of its divisors is an integer number (183695040).

Almost surely, 2^6643915880 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 6643915880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8817361920).

6643915880 is an abundant number, since it is smaller than the sum of its proper divisors (10990807960).

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

6643915880 is a wasteful number, since it uses less digits than its factorization.

6643915880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47839 (or 47828 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 50.

The square root of 6643915880 is about 81510.2194819766. The cubic root of 6643915880 is about 1879.9286867472.

The spelling of 6643915880 in words is "six billion, six hundred forty-three million, nine hundred fifteen thousand, eight hundred eighty".