28111 has 2 divisors, whose sum is σ = 28112. Its totient is φ = 28110.

The previous prime is 28109. The next prime is 28123. The reversal of 28111 is 11182.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28111 - 2¹ = 28109 is a prime.

Together with 28109, it forms a pair of twin primes.

It is a Chen prime.

28111 is a modest number, since divided by 111 gives 28 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 28091 and 28100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28151) 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 as a sum of consecutive naturals, namely, 14055 + 14056.

It is an arithmetic number, because the mean of its divisors is an integer number (14056).

2²⁸¹¹¹ is an apocalyptic number.

28111 is a deficient number, since it is larger than the sum of its proper divisors (1).

28111 is an equidigital number, since it uses as much as digits as its factorization.

28111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16, while the sum is 13.

The square root of 28111 is about 167.6633531813. The cubic root of 28111 is about 30.4059631654.

Adding to 28111 its reverse (11182), we get a palindrome (39293).

It can be divided in two parts, 281 and 11, that added together give a palindrome (292).

The spelling of 28111 in words is "twenty-eight thousand, one hundred eleven".