638865678747 has 8 divisors (see below), whose sum is σ = 854010677520. Its totient is φ = 424815566240.

The previous prime is 638865678727. The next prime is 638865678823. The reversal of 638865678747 is 747876568836.

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

It is a cyclic number.

It is not a de Polignac number, because 638865678747 - 2¹¹ = 638865676699 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638865678727) 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, 273720204 + ... + 273722537.

It is an arithmetic number, because the mean of its divisors is an integer number (106751334690).

Almost surely, 2^638865678747 is an apocalyptic number.

638865678747 is a deficient number, since it is larger than the sum of its proper divisors (215144998773).

638865678747 is a wasteful number, since it uses less digits than its factorization.

638865678747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547443133.

The product of its digits is 2275983360, while the sum is 75.

The spelling of 638865678747 in words is "six hundred thirty-eight billion, eight hundred sixty-five million, six hundred seventy-eight thousand, seven hundred forty-seven".