15891 has 4 divisors (see below), whose sum is σ = 21192. Its totient is φ = 10592.

The previous prime is 15889. The next prime is 15901. The reversal of 15891 is 19851.

15891 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 15891 - 2¹ = 15889 is a prime.

It is a D-number.

15891 is a lucky number.

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (15881) 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, 2646 + ... + 2651.

It is an arithmetic number, because the mean of its divisors is an integer number (5298).

2¹⁵⁸⁹¹ is an apocalyptic number.

15891 is a deficient number, since it is larger than the sum of its proper divisors (5301).

15891 is an equidigital number, since it uses as much as digits as its factorization.

15891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5300.

The product of its digits is 360, while the sum is 24.

The square root of 15891 is about 126.0595097563. The cubic root of 15891 is about 25.1410691492.

The spelling of 15891 in words is "fifteen thousand, eight hundred ninety-one".