638844514387 has 4 divisors (see below), whose sum is σ = 639856946896. Its totient is φ = 637832081880.

The previous prime is 638844514313. The next prime is 638844514393. The reversal of 638844514387 is 783415448836.

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

It is a cyclic number.

It is not a de Polignac number, because 638844514387 - 2¹⁵ = 638844481619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638844514397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 506215308 + ... + 506216569.

It is an arithmetic number, because the mean of its divisors is an integer number (159964236724).

Almost surely, 2^638844514387 is an apocalyptic number.

638844514387 is a deficient number, since it is larger than the sum of its proper divisors (1012432509).

638844514387 is a wasteful number, since it uses less digits than its factorization.

638844514387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1012432508.

The product of its digits is 61931520, while the sum is 61.

The spelling of 638844514387 in words is "six hundred thirty-eight billion, eight hundred forty-four million, five hundred fourteen thousand, three hundred eighty-seven".