285919220 has 54 divisors (see below), whose sum is σ = 636895602. Its totient is φ = 107803872.

The previous prime is 285919213. The next prime is 285919223. The reversal of 285919220 is 22919582.

It can be written as a sum of positive squares in only one way, i.e., 228735376 + 57183844 = 15124^2 + 7562^2 .

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285919223) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1436681 + ... + 1436879.

It is an arithmetic number, because the mean of its divisors is an integer number (11794363).

Almost surely, 2^285919220 is an apocalyptic number.

285919220 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 285919220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (318447801).

285919220 is an abundant number, since it is smaller than the sum of its proper divisors (350976382).

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

285919220 is a wasteful number, since it uses less digits than its factorization.

285919220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445 (or 225 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 285919220 is about 16909.1460458534. The cubic root of 285919220 is about 658.7911911179.

Multiplying 285919220 by its product of nonzero digits (25920), we get a square (7411026182400 = 2722320²).

The spelling of 285919220 in words is "two hundred eighty-five million, nine hundred nineteen thousand, two hundred twenty".