28913 has 4 divisors (see below), whose sum is σ = 29940. Its totient is φ = 27888.

The previous prime is 28909. The next prime is 28921. The reversal of 28913 is 31982.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31982 = 2 ⋅15991.

It can be written as a sum of positive squares in 2 ways, for example, as 20449 + 8464 = 143^2 + 92^2 .

It is a cyclic number.

It is not a de Polignac number, because 28913 - 2² = 28909 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28933) 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, 470 + ... + 527.

It is an arithmetic number, because the mean of its divisors is an integer number (7485).

2²⁸⁹¹³ is an apocalyptic number.

It is an amenable number.

28913 is a deficient number, since it is larger than the sum of its proper divisors (1027).

28913 is an equidigital number, since it uses as much as digits as its factorization.

28913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1026.

The product of its digits is 432, while the sum is 23.

The square root of 28913 is about 170.0382309953. The cubic root of 28913 is about 30.6924143141.

The spelling of 28913 in words is "twenty-eight thousand, nine hundred thirteen".