6646064800 has 72 divisors (see below), whose sum is σ = 16241640156. Its totient is φ = 2655651840.

The previous prime is 6646064791. The next prime is 6646064819. The reversal of 6646064800 is 84606466.

It can be written as a sum of positive squares in 6 ways, for example, as 4089346704 + 2556718096 = 63948^2 + 50564^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 873814 + ... + 881386.

Almost surely, 2^6646064800 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 6646064800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8120820078).

6646064800 is an abundant number, since it is smaller than the sum of its proper divisors (9595575356).

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

6646064800 is a wasteful number, since it uses less digits than its factorization.

6646064800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8690 (or 8677 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 40.

The square root of 6646064800 is about 81523.4003216254. The cubic root of 6646064800 is about 1880.1313473947.

The spelling of 6646064800 in words is "six billion, six hundred forty-six million, sixty-four thousand, eight hundred".