638865332187 has 8 divisors (see below), whose sum is σ = 865784712720. Its totient is φ = 418928086560.

The previous prime is 638865332107. The next prime is 638865332219. The reversal of 638865332187 is 781233568836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 638865332187 - 2¹⁰ = 638865331163 is a prime.

It is a Smith number, since the sum of its digits (60) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 638865332187.

It is not an unprimeable number, because it can be changed into a prime (638865332107) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1745533512 + ... + 1745533877.

It is an arithmetic number, because the mean of its divisors is an integer number (108223089090).

Almost surely, 2^638865332187 is an apocalyptic number.

638865332187 is a deficient number, since it is larger than the sum of its proper divisors (226919380533).

638865332187 is a wasteful number, since it uses less digits than its factorization.

638865332187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3491067453.

The product of its digits is 34836480, while the sum is 60.

The spelling of 638865332187 in words is "six hundred thirty-eight billion, eight hundred sixty-five million, three hundred thirty-two thousand, one hundred eighty-seven".