285660 has 72 divisors (see below), whose sum is σ = 929040. Its totient is φ = 72864.

The previous prime is 285643. The next prime is 285661. The reversal of 285660 is 66582.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285661) by changing a digit.

285660 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12409 + ... + 12431.

2²⁸⁵⁶⁶⁰ is an apocalyptic number.

285660 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 285660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (464520).

285660 is an abundant number, since it is smaller than the sum of its proper divisors (643380).

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

285660 is a wasteful number, since it uses less digits than its factorization.

285660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64 (or 33 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 285660 is about 534.4717017766. The cubic root of 285660 is about 65.8592039895.

It can be divided in two parts, 2856 and 60, that added together give a square (2916 = 54²).

The spelling of 285660 in words is "two hundred eighty-five thousand, six hundred sixty".