6644577785472 has 448 divisors, whose sum is σ = 22790637036000. Its totient is φ = 1907528693760.

The previous prime is 6644577785387. The next prime is 6644577785473. The reversal of 6644577785472 is 2745877754466.

6644577785472 is a `hidden beast` number, since 6 + 6 + 4 + 4 + 5 + 7 + 7 + 78 + 547 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a self number, because there is not a number n which added to its sum of digits gives 6644577785472.

It is not an unprimeable number, because it can be changed into a prime (6644577785473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 19331854 + ... + 19672562.

Almost surely, 2^{6644577785472} 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 6644577785472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11395318518000).

6644577785472 is an abundant number, since it is smaller than the sum of its proper divisors (16146059250528).

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

6644577785472 is a wasteful number, since it uses less digits than its factorization.

6644577785472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340771 (or 340744 counting only the distinct ones).

The product of its digits is 2212761600, while the sum is 72.

The spelling of 6644577785472 in words is "six trillion, six hundred forty-four billion, five hundred seventy-seven million, seven hundred eighty-five thousand, four hundred seventy-two".