640538328584 has 64 divisors (see below), whose sum is σ = 1497493388160. Its totient is φ = 249538544640.

The previous prime is 640538328539. The next prime is 640538328589. The reversal of 640538328584 is 485823835046.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is not an unprimeable number, because it can be changed into a prime (640538328589) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 8213744 + ... + 8291360.

It is an arithmetic number, because the mean of its divisors is an integer number (23398334190).

Almost surely, 2^640538328584 is an apocalyptic number.

It is an amenable number.

640538328584 is an abundant number, since it is smaller than the sum of its proper divisors (856955059576).

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

640538328584 is a wasteful number, since it uses less digits than its factorization.

640538328584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91038 (or 91034 counting only the distinct ones).

The product of its (nonzero) digits is 22118400, while the sum is 56.

The spelling of 640538328584 in words is "six hundred forty billion, five hundred thirty-eight million, three hundred twenty-eight thousand, five hundred eighty-four".