640435570843 has 4 divisors (see below), whose sum is σ = 642125374840. Its totient is φ = 638745766848.

The previous prime is 640435570751. The next prime is 640435570861. The reversal of 640435570843 is 348075534046.

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 640435570843 - 2²⁹ = 639898699931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640435570343) 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, 844901430 + ... + 844902187.

It is an arithmetic number, because the mean of its divisors is an integer number (160531343710).

Almost surely, 2^640435570843 is an apocalyptic number.

640435570843 is a deficient number, since it is larger than the sum of its proper divisors (1689803997).

640435570843 is a wasteful number, since it uses less digits than its factorization.

640435570843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1689803996.

The product of its (nonzero) digits is 4838400, while the sum is 49.

The spelling of 640435570843 in words is "six hundred forty billion, four hundred thirty-five million, five hundred seventy thousand, eight hundred forty-three".