6640255872 has 48 divisors (see below), whose sum is σ = 19108031280. Its totient is φ = 2213418240.

The previous prime is 6640255841. The next prime is 6640255873. The reversal of 6640255872 is 2785520466.

6640255872 is a `hidden beast` number, since 6 + 6 + 40 + 25 + 587 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640255873) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 2880904 + ... + 2883207.

It is an arithmetic number, because the mean of its divisors is an integer number (398083985).

Almost surely, 2^6640255872 is an apocalyptic number.

It is an amenable number.

6640255872 is an abundant number, since it is smaller than the sum of its proper divisors (12467775408).

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

6640255872 is a wasteful number, since it uses less digits than its factorization.

6640255872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5764131 (or 5764116 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 45.

The square root of 6640255872 is about 81487.7651675391. The cubic root of 6640255872 is about 1879.5834175816.

The spelling of 6640255872 in words is "six billion, six hundred forty million, two hundred fifty-five thousand, eight hundred seventy-two".