28939 has 4 divisors (see below), whose sum is σ = 29656. Its totient is φ = 28224.

The previous prime is 28933. The next prime is 28949. The reversal of 28939 is 93982.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a 6-Lehmer number, since φ(28939) divides (28939-1)⁶.

It is a cyclic number.

It is not a de Polignac number, because 28939 - 2¹¹ = 26891 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28939.

It is not an unprimeable number, because it can be changed into a prime (28933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 294 + ... + 379.

It is an arithmetic number, because the mean of its divisors is an integer number (7414).

2²⁸⁹³⁹ is an apocalyptic number.

28939 is a deficient number, since it is larger than the sum of its proper divisors (717).

28939 is an equidigital number, since it uses as much as digits as its factorization.

28939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716.

The product of its digits is 3888, while the sum is 31.

The square root of 28939 is about 170.1146672101. The cubic root of 28939 is about 30.7016116036.

The spelling of 28939 in words is "twenty-eight thousand, nine hundred thirty-nine".