28831 has 4 divisors (see below), whose sum is σ = 31464. Its totient is φ = 26200.

The previous prime is 28817. The next prime is 28837. The reversal of 28831 is 13882.

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 28831 - 2⁷ = 28703 is a prime.

It is a super-2 number, since 2×28831² = 1662453122, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28837) 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, 1300 + ... + 1321.

It is an arithmetic number, because the mean of its divisors is an integer number (7866).

2²⁸⁸³¹ is an apocalyptic number.

28831 is a deficient number, since it is larger than the sum of its proper divisors (2633).

28831 is a wasteful number, since it uses less digits than its factorization.

28831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2632.

The product of its digits is 384, while the sum is 22.

The square root of 28831 is about 169.7969375460. The cubic root of 28831 is about 30.6633713115.

The spelling of 28831 in words is "twenty-eight thousand, eight hundred thirty-one".