128121140 has 96 divisors (see below), whose sum is σ = 323979264. Its totient is φ = 41633280.

The previous prime is 128121139. The next prime is 128121151. The reversal of 128121140 is 41121821.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 229742 + ... + 230298.

It is an arithmetic number, because the mean of its divisors is an integer number (3374784).

Almost surely, 2^128121140 is an apocalyptic number.

128121140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128121140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161989632).

128121140 is an abundant number, since it is smaller than the sum of its proper divisors (195858124).

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

128121140 is a wasteful number, since it uses less digits than its factorization.

128121140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 657 (or 655 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 128121140 is about 11319.0609151113. The cubic root of 128121140 is about 504.1273561166.

Adding to 128121140 its reverse (41121821), we get a palindrome (169242961).

The spelling of 128121140 in words is "one hundred twenty-eight million, one hundred twenty-one thousand, one hundred forty".