128112138 has 96 divisors (see below), whose sum is σ = 357759360. Its totient is φ = 33264000.

The previous prime is 128112133. The next prime is 128112151. The reversal of 128112138 is 831211821.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (128112133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 44338 + ... + 47138.

It is an arithmetic number, because the mean of its divisors is an integer number (3726660).

Almost surely, 2^128112138 is an apocalyptic number.

128112138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 128112138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (178879680).

128112138 is an abundant number, since it is smaller than the sum of its proper divisors (229647222).

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

128112138 is a wasteful number, since it uses less digits than its factorization.

128112138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2841 (or 2824 counting only the distinct ones).

The product of its digits is 768, while the sum is 27.

The square root of 128112138 is about 11318.6632602971. The cubic root of 128112138 is about 504.1155489036.

Adding to 128112138 its reverse (831211821), we get a palindrome (959323959).

The spelling of 128112138 in words is "one hundred twenty-eight million, one hundred twelve thousand, one hundred thirty-eight".