285728220 has 72 divisors (see below), whose sum is σ = 868240464. Its totient is φ = 76059648.

The previous prime is 285728203. The next prime is 285728263. The reversal of 285728220 is 22827582.

285728220 is a `hidden beast` number, since 2 + 8 + 572 + 82 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 140652 + ... + 142668.

Almost surely, 2^285728220 is an apocalyptic number.

285728220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

285728220 is an abundant number, since it is smaller than the sum of its proper divisors (582512244).

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

285728220 is a wasteful number, since it uses less digits than its factorization.

285728220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2819 (or 2814 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 36.

The square root of 285728220 is about 16903.4972712750. The cubic root of 285728220 is about 658.6444630237.

The spelling of 285728220 in words is "two hundred eighty-five million, seven hundred twenty-eight thousand, two hundred twenty".