640859805343 has 4 divisors (see below), whose sum is σ = 646531131168. Its totient is φ = 635188479520.

The previous prime is 640859805317. The next prime is 640859805359. The reversal of 640859805343 is 343508958046.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 640859805343 - 2⁹ = 640859804831 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640859803343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2835662743 + ... + 2835662968.

It is an arithmetic number, because the mean of its divisors is an integer number (161632782792).

Almost surely, 2^640859805343 is an apocalyptic number.

640859805343 is a deficient number, since it is larger than the sum of its proper divisors (5671325825).

640859805343 is a wasteful number, since it uses less digits than its factorization.

640859805343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5671325824.

The product of its (nonzero) digits is 12441600, while the sum is 55.

The spelling of 640859805343 in words is "six hundred forty billion, eight hundred fifty-nine million, eight hundred five thousand, three hundred forty-three".