6644487168 has 132 divisors (see below), whose sum is σ = 20930296608. Its totient is φ = 2013450240.

The previous prime is 6644487103. The next prime is 6644487173. The reversal of 6644487168 is 8617844466.

6644487168 is a `hidden beast` number, since 66 + 44 + 487 + 1 + 68 = 666.

It is a tau number, because it is divible by the number of its divisors (132).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 68605 + ... + 134147.

Almost surely, 2^6644487168 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 6644487168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10465148304).

6644487168 is an abundant number, since it is smaller than the sum of its proper divisors (14285809440).

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

6644487168 is a wasteful number, since it uses less digits than its factorization.

6644487168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65580 (or 65559 counting only the distinct ones).

The product of its digits is 6193152, while the sum is 54.

The square root of 6644487168 is about 81513.7238015783. The cubic root of 6644487168 is about 1879.9825681196.

The spelling of 6644487168 in words is "six billion, six hundred forty-four million, four hundred eighty-seven thousand, one hundred sixty-eight".