28569 has 8 divisors (see below), whose sum is σ = 38880. Its totient is φ = 18656.

The previous prime is 28559. The next prime is 28571. The reversal of 28569 is 96582.

28569 = 31² + 32² + ... + 48².

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28569 - 2⁵ = 28537 is a prime.

It is a super-2 number, since 2×28569² = 1632375522, which contains 22 as substring.

It is a Curzon number.

28569 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (28549) 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, 214 + ... + 320.

It is an arithmetic number, because the mean of its divisors is an integer number (4860).

2²⁸⁵⁶⁹ is an apocalyptic number.

It is an amenable number.

28569 is a deficient number, since it is larger than the sum of its proper divisors (10311).

28569 is a wasteful number, since it uses less digits than its factorization.

28569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199.

The product of its digits is 4320, while the sum is 30.

The square root of 28569 is about 169.0236669819. The cubic root of 28569 is about 30.5702046684.

The spelling of 28569 in words is "twenty-eight thousand, five hundred sixty-nine".