12091 has 4 divisors (see below), whose sum is σ = 12312.
Its totient is φ = 11872.
The previous prime is 12073. The next prime is 12097. The reversal of 12091 is 19021.
It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 19021 = 23 ⋅827.
It is a cyclic number.
It is not a de Polignac number, because 12091 - 29 = 11579 is a prime.
It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.
It is a pancake number, because a pancake can be divided into 12091 parts by 155 straight cuts.
It is a Duffinian number.
It is a plaindrome in base 14.
It is not an unprimeable number, because it can be changed into a prime (12097) 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, 51 + ... + 163.
It is an arithmetic number, because the mean of its divisors is an integer number (3078).
12091 is a Friedman number, since it can be written as 110^2-9, using all its digits and the basic arithmetic operations.
212091 is an apocalyptic number.
12091 is a deficient number, since it is larger than the sum of its proper divisors (221).
12091 is a wasteful number, since it uses less digits than its factorization.
12091 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 220.
The product of its (nonzero) digits is 18, while the sum is 13.
The square root of 12091 is about 109.9590832992.
The cubic root of 12091 is about 22.9520108420.
The spelling of 12091 in words is "twelve thousand, ninety-one".