285491 has 4 divisors (see below), whose sum is σ = 289584. Its totient is φ = 281400.

The previous prime is 285473. The next prime is 285497. The reversal of 285491 is 194582.

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

It is a cyclic number.

It is not a de Polignac number, because 285491 - 2¹⁰ = 284467 is a prime.

It is a super-2 number, since 2×285491² = 163010222162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (285497) 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, 1940 + ... + 2081.

It is an arithmetic number, because the mean of its divisors is an integer number (72396).

2²⁸⁵⁴⁹¹ is an apocalyptic number.

285491 is a deficient number, since it is larger than the sum of its proper divisors (4093).

285491 is an equidigital number, since it uses as much as digits as its factorization.

285491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4092.

The product of its digits is 2880, while the sum is 29.

The square root of 285491 is about 534.3135783414. The cubic root of 285491 is about 65.8462137200.

Subtracting from 285491 its reverse (194582), we obtain a palindrome (90909).

The spelling of 285491 in words is "two hundred eighty-five thousand, four hundred ninety-one".