285138 has 48 divisors (see below), whose sum is σ = 738816. Its totient is φ = 77760.

The previous prime is 285121. The next prime is 285139. The reversal of 285138 is 831582.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (285139) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3870 + ... + 3942.

It is an arithmetic number, because the mean of its divisors is an integer number (15392).

2²⁸⁵¹³⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 285138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (369408).

285138 is an abundant number, since it is smaller than the sum of its proper divisors (453678).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

285138 is a wasteful number, since it uses less digits than its factorization.

285138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119 (or 116 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 285138 is about 533.9831458014. The cubic root of 285138 is about 65.8190636522.

The spelling of 285138 in words is "two hundred eighty-five thousand, one hundred thirty-eight".