128569 has 4 divisors (see below), whose sum is σ = 146944. Its totient is φ = 110196.

The previous prime is 128563. The next prime is 128591. The reversal of 128569 is 965821.

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: 965821 = 17 ⋅56813.

It is a cyclic number.

It is not a de Polignac number, because 128569 - 2¹⁵ = 95801 is a prime.

It is a super-2 number, since 2×128569² = 33059975522, which contains 22 as substring.

It is a plaindrome in base 13.

It is a nialpdrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 128569.

It is not an unprimeable number, because it can be changed into a prime (128563) 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, 9177 + ... + 9190.

It is an arithmetic number, because the mean of its divisors is an integer number (36736).

2¹²⁸⁵⁶⁹ is an apocalyptic number.

It is an amenable number.

128569 is a deficient number, since it is larger than the sum of its proper divisors (18375).

128569 is an equidigital number, since it uses as much as digits as its factorization.

128569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18374.

The product of its digits is 4320, while the sum is 31.

The square root of 128569 is about 358.5651963033. The cubic root of 128569 is about 50.4714081853.

The spelling of 128569 in words is "one hundred twenty-eight thousand, five hundred sixty-nine".