128369 has 4 divisors (see below), whose sum is σ = 129444. Its totient is φ = 127296.

The previous prime is 128351. The next prime is 128377. The reversal of 128369 is 963821.

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, and also an emirpimes, since its reverse is a distinct semiprime: 963821 = 31 ⋅31091.

It can be written as a sum of positive squares in 2 ways, for example, as 35344 + 93025 = 188^2 + 305^2 .

It is a cyclic number.

It is not a de Polignac number, because 128369 - 2⁸ = 128113 is a prime.

It is a super-2 number, since 2×128369² = 32957200322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 332 + ... + 605.

It is an arithmetic number, because the mean of its divisors is an integer number (32361).

2¹²⁸³⁶⁹ is an apocalyptic number.

It is an amenable number.

128369 is a deficient number, since it is larger than the sum of its proper divisors (1075).

128369 is an equidigital number, since it uses as much as digits as its factorization.

128369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1074.

The product of its digits is 2592, while the sum is 29.

The square root of 128369 is about 358.2861984503. The cubic root of 128369 is about 50.4452237491.

The spelling of 128369 in words is "one hundred twenty-eight thousand, three hundred sixty-nine".