640317097728 has 1152 divisors, whose sum is σ = 2469282816000. Its totient is φ = 162163814400.

The previous prime is 640317097723. The next prime is 640317097751. The reversal of 640317097728 is 827790713046.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a super-3 number, since 3×640317097728³ (a number of 36 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640317097723) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1121395683 + ... + 1121396253.

Almost surely, 2^640317097728 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 640317097728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1234641408000).

640317097728 is an abundant number, since it is smaller than the sum of its proper divisors (1828965718272).

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

640317097728 is a wasteful number, since it uses less digits than its factorization.

640317097728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671 (or 637 counting only the distinct ones).

The product of its (nonzero) digits is 3556224, while the sum is 54.

The spelling of 640317097728 in words is "six hundred forty billion, three hundred seventeen million, ninety-seven thousand, seven hundred twenty-eight".