28660 has 12 divisors (see below), whose sum is σ = 60228. Its totient is φ = 11456.

The previous prime is 28657. The next prime is 28661. The reversal of 28660 is 6682.

It can be written as a sum of positive squares in 2 ways, for example, as 17424 + 11236 = 132^2 + 106^2 .

It is a nialpdrome in base 14.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28661) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 697 + ... + 736.

It is an arithmetic number, because the mean of its divisors is an integer number (5019).

2²⁸⁶⁶⁰ is an apocalyptic number.

28660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28660 is an abundant number, since it is smaller than the sum of its proper divisors (31568).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30114).

28660 is a wasteful number, since it uses less digits than its factorization.

28660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1442 (or 1440 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 28660 is about 169.2926460305. The cubic root of 28660 is about 30.6026283928.

Adding to 28660 its sum of digits (22), we get a palindrome (28682).

The spelling of 28660 in words is "twenty-eight thousand, six hundred sixty".