640783383873 has 4 divisors (see below), whose sum is σ = 854377845168. Its totient is φ = 427188922580.

The previous prime is 640783383841. The next prime is 640783383881. The reversal of 640783383873 is 378383387046.

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 640783383873 - 2⁵ = 640783383841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640783383973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106797230643 + ... + 106797230648.

It is an arithmetic number, because the mean of its divisors is an integer number (213594461292).

Almost surely, 2^640783383873 is an apocalyptic number.

It is an amenable number.

640783383873 is a deficient number, since it is larger than the sum of its proper divisors (213594461295).

640783383873 is a wasteful number, since it uses less digits than its factorization.

640783383873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213594461294.

The product of its (nonzero) digits is 48771072, while the sum is 60.

The spelling of 640783383873 in words is "six hundred forty billion, seven hundred eighty-three million, three hundred eighty-three thousand, eight hundred seventy-three".