13891 has 4 divisors (see below), whose sum is σ = 14400.
Its totient is φ = 13384.
The previous prime is 13883. The next prime is 13901. The reversal of 13891 is 19831.
13891 is digitally balanced in base 2, 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, and also an emirpimes, since its reverse is a distinct semiprime: 19831 = 7 ⋅2833.
It is a cyclic number.
It is not a de Polignac number, because 13891 - 23 = 13883 is a prime.
It is a Duffinian number.
It is a nialpdrome in base 7.
It is a zygodrome in base 7.
It is not an unprimeable number, because it can be changed into a prime (13831) 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, 211 + ... + 268.
It is an arithmetic number, because the mean of its divisors is an integer number (3600).
213891 is an apocalyptic number.
13891 is a deficient number, since it is larger than the sum of its proper divisors (509).
13891 is an equidigital number, since it uses as much as digits as its factorization.
13891 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 508.
The product of its digits is 216, while the sum is 22.
The square root of 13891 is about 117.8600865433.
The cubic root of 13891 is about 24.0387106764.
The spelling of 13891 in words is "thirteen thousand, eight hundred ninety-one".