6643982016 has 224 divisors, whose sum is σ = 23498048000. Its totient is φ = 1798308864.

The previous prime is 6643981999. The next prime is 6643982017. The reversal of 6643982016 is 6102893466.

6643982016 is a `hidden beast` number, since 6 + 6 + 439 + 8 + 201 + 6 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (6643982017) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 215370 + ... + 244278.

It is an arithmetic number, because the mean of its divisors is an integer number (104902000).

Almost surely, 2^6643982016 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 6643982016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11749024000).

6643982016 is an abundant number, since it is smaller than the sum of its proper divisors (16854065984).

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

6643982016 is a wasteful number, since it uses less digits than its factorization.

6643982016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28956 (or 28940 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The square root of 6643982016 is about 81510.6251724277. The cubic root of 6643982016 is about 1879.9349245620.

The spelling of 6643982016 in words is "six billion, six hundred forty-three million, nine hundred eighty-two thousand, sixteen".