640564042788 has 36 divisors (see below), whose sum is σ = 1689603709248. Its totient is φ = 204237810480.

The previous prime is 640564042763. The next prime is 640564042793. The reversal of 640564042788 is 887240465046.

It is a happy number.

640564042788 is a `hidden beast` number, since 6 + 4 + 0 + 564 + 0 + 4 + 2 + 78 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 386813208 + ... + 386814863.

It is an arithmetic number, because the mean of its divisors is an integer number (46933436368).

Almost surely, 2^640564042788 is an apocalyptic number.

It is an amenable number.

640564042788 is an abundant number, since it is smaller than the sum of its proper divisors (1049039666460).

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

640564042788 is a wasteful number, since it uses less digits than its factorization.

640564042788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773628104 (or 773628099 counting only the distinct ones).

The product of its (nonzero) digits is 10321920, while the sum is 54.

The spelling of 640564042788 in words is "six hundred forty billion, five hundred sixty-four million, forty-two thousand, seven hundred eighty-eight".