28911 has 8 divisors (see below), whose sum is σ = 40320. Its totient is φ = 18392.

The previous prime is 28909. The next prime is 28921. The reversal of 28911 is 11982.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28911 - 2¹ = 28909 is a prime.

It is a nialpdrome in base 14 and base 15.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 28911.

It is not an unprimeable number, because it can be changed into a prime (28901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 141 + ... + 278.

It is an arithmetic number, because the mean of its divisors is an integer number (5040).

2²⁸⁹¹¹ is an apocalyptic number.

28911 is a deficient number, since it is larger than the sum of its proper divisors (11409).

28911 is a wasteful number, since it uses less digits than its factorization.

28911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445.

The product of its digits is 144, while the sum is 21.

The square root of 28911 is about 170.0323498632. The cubic root of 28911 is about 30.6917066020.

It can be divided in two parts, 289 and 11, that added together give a triangular number (300 = T₂₄).

The spelling of 28911 in words is "twenty-eight thousand, nine hundred eleven".