638865678675 has 144 divisors (see below), whose sum is σ = 1250278310400. Its totient is φ = 286961875200.

The previous prime is 638865678641. The next prime is 638865678691. The reversal of 638865678675 is 576876568836.

It is not a de Polignac number, because 638865678675 - 2¹³ = 638865670483 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (75).

It is a junction number, because it is equal to n+sod(n) for n = 638865678597 and 638865678606.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 61253361 + ... + 61263789.

Almost surely, 2^638865678675 is an apocalyptic number.

638865678675 is a deficient number, since it is larger than the sum of its proper divisors (611412631725).

638865678675 is a wasteful number, since it uses less digits than its factorization.

638865678675 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10746 (or 10734 counting only the distinct ones).

The product of its digits is 2438553600, while the sum is 75.

The spelling of 638865678675 in words is "six hundred thirty-eight billion, eight hundred sixty-five million, six hundred seventy-eight thousand, six hundred seventy-five".