28947 has 4 divisors (see below), whose sum is σ = 38600. Its totient is φ = 19296.

The previous prime is 28933. The next prime is 28949. The reversal of 28947 is 74982.

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

It is not a de Polignac number, because 28947 - 2¹² = 24851 is a prime.

It is a D-number.

It is a Duffinian number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (28949) 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, 4822 + ... + 4827.

It is an arithmetic number, because the mean of its divisors is an integer number (9650).

2²⁸⁹⁴⁷ is an apocalyptic number.

28947 is a deficient number, since it is larger than the sum of its proper divisors (9653).

28947 is an equidigital number, since it uses as much as digits as its factorization.

28947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9652.

The product of its digits is 4032, while the sum is 30.

The square root of 28947 is about 170.1381791368. The cubic root of 28947 is about 30.7044404305.

The spelling of 28947 in words is "twenty-eight thousand, nine hundred forty-seven".