Subtracting from 28691 its reverse (19682), we obtain a palindrome (9009).
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is a Duffinian number.
It is a nialpdrome in base 14.
It is a self number, because there is not a number n which added to its sum of digits gives 28691.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 28691.
228691 is an apocalyptic number.
28691 is a wasteful number, since it uses less digits than its factorization.
28691 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 2220.
The square root of 28691 is about 169.3841787181. The cubic root of 28691 is about 30.6136581630.
The spelling of 28691 in words is "twenty-eight thousand, six hundred ninety-one".