640020542873 has 4 divisors (see below), whose sum is σ = 653638001280. Its totient is φ = 626403084468.

The previous prime is 640020542831. The next prime is 640020542929. The reversal of 640020542873 is 378245020046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 640020542873 - 2¹² = 640020538777 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 640020542873.

It is not an unprimeable number, because it can be changed into a prime (640020545873) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 6808729133 + ... + 6808729226.

It is an arithmetic number, because the mean of its divisors is an integer number (163409500320).

Almost surely, 2^640020542873 is an apocalyptic number.

It is an amenable number.

640020542873 is a deficient number, since it is larger than the sum of its proper divisors (13617458407).

640020542873 is a wasteful number, since it uses less digits than its factorization.

640020542873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13617458406.

The product of its (nonzero) digits is 322560, while the sum is 41.

The spelling of 640020542873 in words is "six hundred forty billion, twenty million, five hundred forty-two thousand, eight hundred seventy-three".