640632254263 has 4 divisors (see below), whose sum is σ = 641052894168. Its totient is φ = 640211614360.

The previous prime is 640632254257. The next prime is 640632254291. The reversal of 640632254263 is 362452236046.

640632254263 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640632254263 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 (640632257263) 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, 210317668 + ... + 210320713.

It is an arithmetic number, because the mean of its divisors is an integer number (160263223542).

Almost surely, 2^640632254263 is an apocalyptic number.

640632254263 is a deficient number, since it is larger than the sum of its proper divisors (420639905).

640632254263 is a wasteful number, since it uses less digits than its factorization.

640632254263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420639904.

The product of its (nonzero) digits is 1244160, while the sum is 43.

The spelling of 640632254263 in words is "six hundred forty billion, six hundred thirty-two million, two hundred fifty-four thousand, two hundred sixty-three".