6638005945728 has 768 divisors, whose sum is σ = 21628830263040. Its totient is φ = 2018286305280.

The previous prime is 6638005945723. The next prime is 6638005945751. The reversal of 6638005945728 is 8275495008366.

It is a happy number.

6638005945728 is a `hidden beast` number, since 6 + 6 + 3 + 8 + 0 + 0 + 59 + 4 + 572 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6638005945723) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3114971223 + ... + 3114973353.

It is an arithmetic number, because the mean of its divisors is an integer number (28162539405).

Almost surely, 2^{6638005945728} is an apocalyptic number.

6638005945728 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6638005945728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10814415131520).

6638005945728 is an abundant number, since it is smaller than the sum of its proper divisors (14990824317312).

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

6638005945728 is a wasteful number, since it uses less digits than its factorization.

6638005945728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2357 (or 2333 counting only the distinct ones).

The product of its (nonzero) digits is 87091200, while the sum is 63.

The spelling of 6638005945728 in words is "six trillion, six hundred thirty-eight billion, five million, nine hundred forty-five thousand, seven hundred twenty-eight".