8638969371138 has 18 divisors (see below), whose sum is σ = 18717793989219. Its totient is φ = 2879652300372.

The previous prime is 8638969371119. The next prime is 8638969371157. The reversal of 8638969371138 is 8311739698368.

8638969371138 is a `hidden beast` number, since 8 + 6 + 38 + 96 + 9 + 371 + 138 = 666.

It is an interprime number because it is at equal distance from previous prime (8638969371119) and next prime (8638969371157).

It can be written as a sum of positive squares in only one way, i.e., 4319484685569 + 4319484685569 = 2078337^2 + 2078337^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=2078337.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 12123633 + ... + 12816411.

Almost surely, 2^{8638969371138} is an apocalyptic number.

8638969371138 is an abundant number, since it is smaller than the sum of its proper divisors (10078824618081).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8638969371138 is an frugal number, since it uses more digits than its factorization.

8638969371138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1385566 (or 692784 counting only the distinct ones).

The product of its digits is 282175488, while the sum is 72.

Multiplying 8638969371138 by its sum of digits (72), we get a square (622005794721936 = 24940044²).

The spelling of 8638969371138 in words is "eight trillion, six hundred thirty-eight billion, nine hundred sixty-nine million, three hundred seventy-one thousand, one hundred thirty-eight".