28909 has 2 divisors, whose sum is σ = 28910. Its totient is φ = 28908.

The previous prime is 28901. The next prime is 28921. The reversal of 28909 is 90982.

It is a happy number.

28909 is nontrivially palindromic in base 11.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28900 + 9 = 170^2 + 3^2 .

It is a cyclic number.

It is not a de Polignac number, because 28909 - 2³ = 28901 is a prime.

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14454 + 14455.

It is an arithmetic number, because the mean of its divisors is an integer number (14455).

2²⁸⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

28909 is a deficient number, since it is larger than the sum of its proper divisors (1).

28909 is an equidigital number, since it uses as much as digits as its factorization.

28909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 28909 is about 170.0264685277. The cubic root of 28909 is about 30.6909988572.

It can be divided in two parts, 28 and 909, that multiplied together give a palindrome (25452).

The spelling of 28909 in words is "twenty-eight thousand, nine hundred nine".