640250855805 has 16 divisors (see below), whose sum is σ = 1117528766784. Its totient is φ = 310424657280.

The previous prime is 640250855791. The next prime is 640250855861. The reversal of 640250855805 is 508558052046.

640250855805 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 640250855805 - 2²⁰ = 640249807229 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1940153944 + ... + 1940154273.

It is an arithmetic number, because the mean of its divisors is an integer number (69845547924).

Almost surely, 2^640250855805 is an apocalyptic number.

It is an amenable number.

640250855805 is a deficient number, since it is larger than the sum of its proper divisors (477277910979).

640250855805 is a wasteful number, since it uses less digits than its factorization.

640250855805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3880308236.

The product of its (nonzero) digits is 1920000, while the sum is 48.

The spelling of 640250855805 in words is "six hundred forty billion, two hundred fifty million, eight hundred fifty-five thousand, eight hundred five".