285207220 has 24 divisors (see below), whose sum is σ = 604434600. Its totient is φ = 113035392.

The previous prime is 285207217. The next prime is 285207229. The reversal of 285207220 is 22702582.

It can be written as a sum of positive squares in 4 ways, for example, as 12759184 + 272448036 = 3572^2 + 16506^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285207229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63235 + ... + 67594.

It is an arithmetic number, because the mean of its divisors is an integer number (25184775).

Almost surely, 2^285207220 is an apocalyptic number.

285207220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

285207220 is an abundant number, since it is smaller than the sum of its proper divisors (319227380).

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

285207220 is a wasteful number, since it uses less digits than its factorization.

285207220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130947 (or 130945 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 28.

The square root of 285207220 is about 16888.0792276683. The cubic root of 285207220 is about 658.2438929215.

The spelling of 285207220 in words is "two hundred eighty-five million, two hundred seven thousand, two hundred twenty".