6639320646 has 96 divisors (see below), whose sum is σ = 16734332160. Its totient is φ = 1863183168.

The previous prime is 6639320629. The next prime is 6639320659. The reversal of 6639320646 is 6460239366.

It is a happy number.

6639320646 is a `hidden beast` number, since 6 + 639 + 3 + 2 + 0 + 6 + 4 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3536260 + ... + 3538136.

It is an arithmetic number, because the mean of its divisors is an integer number (174315960).

Almost surely, 2^6639320646 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6639320646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8367166080).

6639320646 is an abundant number, since it is smaller than the sum of its proper divisors (10095011514).

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

6639320646 is a wasteful number, since it uses less digits than its factorization.

6639320646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2378 (or 2375 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 45.

The square root of 6639320646 is about 81482.0265211905. The cubic root of 6639320646 is about 1879.4951720960.

The spelling of 6639320646 in words is "six billion, six hundred thirty-nine million, three hundred twenty thousand, six hundred forty-six".