640128419784 has 256 divisors, whose sum is σ = 2099349504000. Its totient is φ = 176855477760.

The previous prime is 640128419741. The next prime is 640128419803. The reversal of 640128419784 is 487914821046.

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

It is a self number, because there is not a number n which added to its sum of digits gives 640128419784.

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, 69506572 + ... + 69515780.

It is an arithmetic number, because the mean of its divisors is an integer number (8200584000).

Almost surely, 2^640128419784 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 640128419784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1049674752000).

640128419784 is an abundant number, since it is smaller than the sum of its proper divisors (1459221084216).

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

640128419784 is a wasteful number, since it uses less digits than its factorization.

640128419784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10745 (or 10735 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 54.

The spelling of 640128419784 in words is "six hundred forty billion, one hundred twenty-eight million, four hundred nineteen thousand, seven hundred eighty-four".