138880128 has 64 divisors (see below), whose sum is σ = 370235520. Its totient is φ = 46126080.

The previous prime is 138880121. The next prime is 138880169. The reversal of 138880128 is 821088831.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (138880121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151993 + ... + 152903.

It is an arithmetic number, because the mean of its divisors is an integer number (5784930).

Almost surely, 2^138880128 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 138880128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (185117760).

138880128 is an abundant number, since it is smaller than the sum of its proper divisors (231355392).

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

138880128 is an equidigital number, since it uses as much as digits as its factorization.

138880128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1325 (or 1313 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 39.

The square root of 138880128 is about 11784.7413208776. The cubic root of 138880128 is about 517.8611952492.

The spelling of 138880128 in words is "one hundred thirty-eight million, eight hundred eighty thousand, one hundred twenty-eight".