638584844813 has 16 divisors (see below), whose sum is σ = 667480214016. Its totient is φ = 610215870720.

The previous prime is 638584844773. The next prime is 638584844819. The reversal of 638584844813 is 318448485836.

It is a cyclic number.

It is not a de Polignac number, because 638584844813 - 2¹⁰ = 638584843789 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 (638584844819) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4857281 + ... + 4987017.

It is an arithmetic number, because the mean of its divisors is an integer number (41717513376).

Almost surely, 2^638584844813 is an apocalyptic number.

It is an amenable number.

638584844813 is a deficient number, since it is larger than the sum of its proper divisors (28895369203).

638584844813 is a wasteful number, since it uses less digits than its factorization.

638584844813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131764.

The product of its digits is 70778880, while the sum is 62.

The spelling of 638584844813 in words is "six hundred thirty-eight billion, five hundred eighty-four million, eight hundred forty-four thousand, eight hundred thirteen".