28739 has 4 divisors (see below), whose sum is σ = 29760. Its totient is φ = 27720.

The previous prime is 28729. The next prime is 28751. The reversal of 28739 is 93782.

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

It is a cyclic number.

It is not a de Polignac number, because 28739 - 2⁴ = 28723 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 991 = 28739 / (2 + 8 + 7 + 3 + 9).

It is a d-powerful number, because it can be written as 2¹³ + 8³ + 7³ + 3⁹ + 9 .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28729) 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, 467 + ... + 524.

It is an arithmetic number, because the mean of its divisors is an integer number (7440).

2²⁸⁷³⁹ is an apocalyptic number.

28739 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

28739 is a deficient number, since it is larger than the sum of its proper divisors (1021).

28739 is an equidigital number, since it uses as much as digits as its factorization.

28739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1020.

The product of its digits is 3024, while the sum is 29.

The square root of 28739 is about 169.5258092445. The cubic root of 28739 is about 30.6307208527.

It can be divided in two parts, 2873 and 9, that added together give a palindrome (2882).

The spelling of 28739 in words is "twenty-eight thousand, seven hundred thirty-nine".