128143121 has 4 divisors (see below), whose sum is σ = 128420352. Its totient is φ = 127865892.

The previous prime is 128143117. The next prime is 128143123. The reversal of 128143121 is 121341821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 121341821 = 3499 ⋅34679.

It is a cyclic number.

It is not a de Polignac number, because 128143121 - 2² = 128143117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128143123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137921 + ... + 138846.

It is an arithmetic number, because the mean of its divisors is an integer number (32105088).

Almost surely, 2^128143121 is an apocalyptic number.

It is an amenable number.

128143121 is a deficient number, since it is larger than the sum of its proper divisors (277231).

128143121 is an equidigital number, since it uses as much as digits as its factorization.

128143121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277230.

The product of its digits is 384, while the sum is 23.

The square root of 128143121 is about 11320.0318462450. The cubic root of 128143121 is about 504.1561845357.

Adding to 128143121 its reverse (121341821), we get a palindrome (249484942).

The spelling of 128143121 in words is "one hundred twenty-eight million, one hundred forty-three thousand, one hundred twenty-one".