11491 has 2 divisors, whose sum is σ = 11492.
Its totient is φ = 11490.
The previous prime is 11489. The next prime is 11497. The reversal of 11491 is 19411.
It is a happy number.
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 11491 - 21 = 11489 is a prime.
Together with 11489, it forms a pair of twin primes.
11491 is a lucky number.
It is a plaindrome in base 9.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 11491.
It is not a weakly prime, because it can be changed into another prime (11497) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5745 + 5746.
It is an arithmetic number, because the mean of its divisors is an integer number (5746).
211491 is an apocalyptic number.
11491 is a deficient number, since it is larger than the sum of its proper divisors (1).
11491 is an equidigital number, since it uses as much as digits as its factorization.
11491 is an evil number, because the sum of its binary digits is even.
The product of its digits is 36, while the sum is 16.
The square root of 11491 is about 107.1960820180.
The cubic root of 11491 is about 22.5658973483.
The spelling of 11491 in words is "eleven thousand, four hundred ninety-one".