285109 has 4 divisors (see below), whose sum is σ = 311040. Its totient is φ = 259180.

The previous prime is 285101. The next prime is 285113. The reversal of 285109 is 901582.

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.

It is a cyclic number.

It is not a de Polignac number, because 285109 - 2³ = 285101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285101) 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, 12949 + ... + 12970.

It is an arithmetic number, because the mean of its divisors is an integer number (77760).

2²⁸⁵¹⁰⁹ is an apocalyptic number.

It is an amenable number.

285109 is a deficient number, since it is larger than the sum of its proper divisors (25931).

285109 is a wasteful number, since it uses less digits than its factorization.

285109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25930.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 285109 is about 533.9559906959. The cubic root of 285109 is about 65.8168321975.

The spelling of 285109 in words is "two hundred eighty-five thousand, one hundred nine".