12138944538 has 48 divisors (see below), whose sum is σ = 28930474944. Its totient is φ = 3383674560.

The previous prime is 12138944533. The next prime is 12138944603. The reversal of 12138944538 is 83544983121.

It is not an unprimeable number, because it can be changed into a prime (12138944533) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 491470 + ... + 515577.

It is an arithmetic number, because the mean of its divisors is an integer number (602718228).

Almost surely, 2^12138944538 is an apocalyptic number.

12138944538 is an abundant number, since it is smaller than the sum of its proper divisors (16791530406).

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

12138944538 is a wasteful number, since it uses less digits than its factorization.

12138944538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1007107 (or 1007100 counting only the distinct ones).

The product of its digits is 829440, while the sum is 48.

The spelling of 12138944538 in words is "twelve billion, one hundred thirty-eight million, nine hundred forty-four thousand, five hundred thirty-eight".