28761 has 4 divisors (see below), whose sum is σ = 38352. Its totient is φ = 19172.

The previous prime is 28759. The next prime is 28771. The reversal of 28761 is 16782.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28761 - 2¹ = 28759 is a prime.

It is a D-number.

It is a plaindrome in base 12.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 28761.

It is not an unprimeable number, because it can be changed into a prime (28711) 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, 4791 + ... + 4796.

It is an arithmetic number, because the mean of its divisors is an integer number (9588).

2²⁸⁷⁶¹ is an apocalyptic number.

It is an amenable number.

28761 is a deficient number, since it is larger than the sum of its proper divisors (9591).

28761 is an equidigital number, since it uses as much as digits as its factorization.

28761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9590.

The product of its digits is 672, while the sum is 24.

The square root of 28761 is about 169.5906837064. The cubic root of 28761 is about 30.6385349030.

The spelling of 28761 in words is "twenty-eight thousand, seven hundred sixty-one".