640517493 has 48 divisors (see below), whose sum is σ = 1129372160. Its totient is φ = 315200160.

The previous prime is 640517489. The next prime is 640517503. The reversal of 640517493 is 394715046.

640517493 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 640517493 - 2² = 640517489 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640517413) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 41646 + ... + 54912.

Almost surely, 2^640517493 is an apocalyptic number.

It is an amenable number.

640517493 is a deficient number, since it is larger than the sum of its proper divisors (488854667).

640517493 is a wasteful number, since it uses less digits than its factorization.

640517493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13318 (or 13307 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 39.

The square root of 640517493 is about 25308.4470681233. The cubic root of 640517493 is about 862.0060852853.

The spelling of 640517493 in words is "six hundred forty million, five hundred seventeen thousand, four hundred ninety-three".