640653517439 has 16 divisors (see below), whose sum is σ = 731548013280. Its totient is φ = 556158182400.

The previous prime is 640653517423. The next prime is 640653517523. The reversal of 640653517439 is 934715356046.

It is a cyclic number.

It is not a de Polignac number, because 640653517439 - 2⁴ = 640653517423 is a prime.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640653517409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9432362 + ... + 9500039.

It is an arithmetic number, because the mean of its divisors is an integer number (45721750830).

Almost surely, 2^640653517439 is an apocalyptic number.

640653517439 is a deficient number, since it is larger than the sum of its proper divisors (90894495841).

640653517439 is a wasteful number, since it uses less digits than its factorization.

640653517439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18932570.

The product of its (nonzero) digits is 8164800, while the sum is 53.

The spelling of 640653517439 in words is "six hundred forty billion, six hundred fifty-three million, five hundred seventeen thousand, four hundred thirty-nine".