12138728665428 has 48 divisors (see below), whose sum is σ = 32555977272000. Its totient is φ = 3906717270624.

The previous prime is 12138728665403. The next prime is 12138728665447. The reversal of 12138728665428 is 82456682783121.

12138728665428 is a `hidden beast` number, since 1 + 2 + 1 + 3 + 8 + 7 + 2 + 86 + 6 + 542 + 8 = 666.

It is a super-3 number, since 3×12138728665428³ (a number of 40 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1937852658 + ... + 1937858921.

It is an arithmetic number, because the mean of its divisors is an integer number (678249526500).

Almost surely, 2^{12138728665428} is an apocalyptic number.

12138728665428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

12138728665428 is an abundant number, since it is smaller than the sum of its proper divisors (20417248606572).

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

12138728665428 is a wasteful number, since it uses less digits than its factorization.

12138728665428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3875711621 (or 3875711613 counting only the distinct ones).

The product of its digits is 61931520, while the sum is 63.

The spelling of 12138728665428 in words is "twelve trillion, one hundred thirty-eight billion, seven hundred twenty-eight million, six hundred sixty-five thousand, four hundred twenty-eight".