285420 has 48 divisors (see below), whose sum is σ = 822528. Its totient is φ = 73920.

The previous prime is 285377. The next prime is 285421. The reversal of 285420 is 24582.

285420 = 25² + 26² + ... + 95².

It is not an unprimeable number, because it can be changed into a prime (285421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3985 + ... + 4055.

It is an arithmetic number, because the mean of its divisors is an integer number (17136).

2²⁸⁵⁴²⁰ is an apocalyptic number.

285420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 285420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (411264).

285420 is an abundant number, since it is smaller than the sum of its proper divisors (537108).

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

285420 is a wasteful number, since it uses less digits than its factorization.

285420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 285420 is about 534.2471338248. The cubic root of 285420 is about 65.8407547403.

The spelling of 285420 in words is "two hundred eighty-five thousand, four hundred twenty".