285661728 has 240 divisors, whose sum is σ = 941836896. Its totient is φ = 84188160.

The previous prime is 285661721. The next prime is 285661729. The reversal of 285661728 is 827166582.

285661728 is a `hidden beast` number, since 2 + 8 + 5 + 6 + 617 + 28 = 666.

It is not an unprimeable number, because it can be changed into a prime (285661721) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1225900 + ... + 1226132.

Almost surely, 2^285661728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 285661728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (470918448).

285661728 is an abundant number, since it is smaller than the sum of its proper divisors (656175168).

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

285661728 is a wasteful number, since it uses less digits than its factorization.

285661728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309 (or 292 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 285661728 is about 16901.5303449126. The cubic root of 285661728 is about 658.5933678662.

The spelling of 285661728 in words is "two hundred eighty-five million, six hundred sixty-one thousand, seven hundred twenty-eight".