285638 has 8 divisors (see below), whose sum is σ = 430920. Its totient is φ = 142000.

The previous prime is 285631. The next prime is 285641. The reversal of 285638 is 836582.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-4 number, since 4×285638⁴ (a number of 23 digits) contains 4444 as substring.

It is a d-powerful number, because it can be written as 2¹¹ + 8 + 6⁷ + 5⁵ + 3² + 8³ .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285631) by changing a digit.

285638 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 218 + ... + 786.

It is an arithmetic number, because the mean of its divisors is an integer number (53865).

2²⁸⁵⁶³⁸ is an apocalyptic number.

285638 is a deficient number, since it is larger than the sum of its proper divisors (145282).

285638 is a wasteful number, since it uses less digits than its factorization.

285638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 822.

The product of its digits is 11520, while the sum is 32.

The square root of 285638 is about 534.4511203094. The cubic root of 285638 is about 65.8575132386.

The spelling of 285638 in words is "two hundred eighty-five thousand, six hundred thirty-eight".