138740128 has 96 divisors (see below), whose sum is σ = 314979840. Its totient is φ = 59719680.

The previous prime is 138740123. The next prime is 138740131. The reversal of 138740128 is 821047831.

It is a happy number.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 138740093 and 138740102.

It is not an unprimeable number, because it can be changed into a prime (138740123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 320200 + ... + 320632.

It is an arithmetic number, because the mean of its divisors is an integer number (3281040).

Almost surely, 2^138740128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138740128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (157489920).

138740128 is an abundant number, since it is smaller than the sum of its proper divisors (176239712).

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

138740128 is a wasteful number, since it uses less digits than its factorization.

138740128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510 (or 502 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 138740128 is about 11778.7999388732. The cubic root of 138740128 is about 517.6871244066.

Adding to 138740128 its reverse (821047831), we get a palindrome (959787959).

The spelling of 138740128 in words is "one hundred thirty-eight million, seven hundred forty thousand, one hundred twenty-eight".