128423121 has 16 divisors (see below), whose sum is σ = 174255168. Its totient is φ = 84110400.

The previous prime is 128423089. The next prime is 128423143. The reversal of 128423121 is 121324821.

It is not a de Polignac number, because 128423121 - 2⁵ = 128423089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128423091 and 128423100.

It is not an unprimeable number, because it can be changed into a prime (128423171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108151 + ... + 109331.

It is an arithmetic number, because the mean of its divisors is an integer number (10890948).

Almost surely, 2^128423121 is an apocalyptic number.

It is an amenable number.

128423121 is a deficient number, since it is larger than the sum of its proper divisors (45832047).

128423121 is a wasteful number, since it uses less digits than its factorization.

128423121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1792.

The product of its digits is 768, while the sum is 24.

The square root of 128423121 is about 11332.3925540902. The cubic root of 128423121 is about 504.5231207090.

Adding to 128423121 its reverse (121324821), we get a palindrome (249747942).

The spelling of 128423121 in words is "one hundred twenty-eight million, four hundred twenty-three thousand, one hundred twenty-one".