640556928336 has 320 divisors, whose sum is σ = 2002971801600. Its totient is φ = 174445996032.

The previous prime is 640556928301. The next prime is 640556928353. The reversal of 640556928336 is 633829655046.

It is a hoax number, since the sum of its digits (57) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11698270 + ... + 11752898.

It is an arithmetic number, because the mean of its divisors is an integer number (6259286880).

Almost surely, 2^640556928336 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 640556928336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1001485900800).

640556928336 is an abundant number, since it is smaller than the sum of its proper divisors (1362414873264).

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

640556928336 is a wasteful number, since it uses less digits than its factorization.

640556928336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54738 (or 54732 counting only the distinct ones).

The product of its (nonzero) digits is 27993600, while the sum is 57.

The spelling of 640556928336 in words is "six hundred forty billion, five hundred fifty-six million, nine hundred twenty-eight thousand, three hundred thirty-six".