28129 has 4 divisors (see below), whose sum is σ = 29376. Its totient is φ = 26884.

The previous prime is 28123. The next prime is 28151. The reversal of 28129 is 92182.

28129 is nontrivially palindromic in base 9 and base 12.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 92182 = 2 ⋅46091.

It is a cyclic number.

It is not a de Polignac number, because 28129 - 2⁵ = 28097 is a prime.

It is a Duffinian number.

28129 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (28123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 589 + ... + 634.

It is an arithmetic number, because the mean of its divisors is an integer number (7344).

2²⁸¹²⁹ is an apocalyptic number.

It is an amenable number.

28129 is a deficient number, since it is larger than the sum of its proper divisors (1247).

28129 is a wasteful number, since it uses less digits than its factorization.

28129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1246.

The product of its digits is 288, while the sum is 22.

The square root of 28129 is about 167.7170235844. The cubic root of 28129 is about 30.4124516167.

The spelling of 28129 in words is "twenty-eight thousand, one hundred twenty-nine".