285409 has 4 divisors (see below), whose sum is σ = 286740. Its totient is φ = 284080.

The previous prime is 285377. The next prime is 285421. The reversal of 285409 is 904582.

It is a happy number.

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 91809 + 193600 = 303^2 + 440^2 .

It is a cyclic number.

It is not a de Polignac number, because 285409 - 2⁵ = 285377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (285469) 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, 262 + ... + 799.

It is an arithmetic number, because the mean of its divisors is an integer number (71685).

2²⁸⁵⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

285409 is a deficient number, since it is larger than the sum of its proper divisors (1331).

285409 is a wasteful number, since it uses less digits than its factorization.

285409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1330.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 285409 is about 534.2368388646. The cubic root of 285409 is about 65.8399089019.

The spelling of 285409 in words is "two hundred eighty-five thousand, four hundred nine".