128285 has 4 divisors (see below), whose sum is σ = 153948. Its totient is φ = 102624.

The previous prime is 128273. The next prime is 128287. The reversal of 128285 is 582821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 42436 + 85849 = 206^2 + 293^2 .

It is a cyclic number.

It is not a de Polignac number, because 128285 - 2⁶ = 128221 is a prime.

It is a super-3 number, since 3×128285³ = 6333574600647375, which contains 333 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 (128287) 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, 12824 + ... + 12833.

It is an arithmetic number, because the mean of its divisors is an integer number (38487).

2¹²⁸²⁸⁵ is an apocalyptic number.

It is an amenable number.

128285 is a deficient number, since it is larger than the sum of its proper divisors (25663).

128285 is an equidigital number, since it uses as much as digits as its factorization.

128285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25662.

The product of its digits is 1280, while the sum is 26.

The square root of 128285 is about 358.1689545452. The cubic root of 128285 is about 50.4342181755.

The spelling of 128285 in words is "one hundred twenty-eight thousand, two hundred eighty-five".