128423 has 4 divisors (see below), whose sum is σ = 129360. Its totient is φ = 127488.

The previous prime is 128413. The next prime is 128431. The reversal of 128423 is 324821.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 128423 - 2¹⁰ = 127399 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 128395 and 128404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128413) 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, 218 + ... + 551.

It is an arithmetic number, because the mean of its divisors is an integer number (32340).

2¹²⁸⁴²³ is an apocalyptic number.

128423 is a deficient number, since it is larger than the sum of its proper divisors (937).

128423 is an equidigital number, since it uses as much as digits as its factorization.

128423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936.

The product of its digits is 384, while the sum is 20.

The square root of 128423 is about 358.3615492767. The cubic root of 128423 is about 50.4522962255.

The spelling of 128423 in words is "one hundred twenty-eight thousand, four hundred twenty-three".