640193831784 has 96 divisors (see below), whose sum is σ = 1873877733000. Its totient is φ = 196281630720.

The previous prime is 640193831677. The next prime is 640193831801. The reversal of 640193831784 is 487138391046.

640193831784 is a `hidden beast` number, since 6 + 401 + 93 + 83 + 1 + 78 + 4 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 585821852100 + 54371979684 = 765390^2 + 233178^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 640193831784.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 954009 + ... + 1480040.

Almost surely, 2^640193831784 is an apocalyptic number.

It is an amenable number.

640193831784 is an abundant number, since it is smaller than the sum of its proper divisors (1233683901216).

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

640193831784 is a wasteful number, since it uses less digits than its factorization.

640193831784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2434355 (or 2434348 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The spelling of 640193831784 in words is "six hundred forty billion, one hundred ninety-three million, eight hundred thirty-one thousand, seven hundred eighty-four".