640322713728 has 448 divisors, whose sum is σ = 2045277561600. Its totient is φ = 198884450304.

The previous prime is 640322713703. The next prime is 640322713783. The reversal of 640322713728 is 827317223046.

640322713728 is a `hidden beast` number, since 6 + 4 + 0 + 3 + 2 + 271 + 372 + 8 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 163387353 + ... + 163391271.

It is an arithmetic number, because the mean of its divisors is an integer number (4565351700).

Almost surely, 2^640322713728 is an apocalyptic number.

640322713728 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640322713728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1022638780800).

640322713728 is an abundant number, since it is smaller than the sum of its proper divisors (1404954847872).

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

640322713728 is a wasteful number, since it uses less digits than its factorization.

640322713728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4071 (or 4044 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 45.

The spelling of 640322713728 in words is "six hundred forty billion, three hundred twenty-two million, seven hundred thirteen thousand, seven hundred twenty-eight".