65491 has 4 divisors (see below), whose sum is σ = 66400.
Its totient is φ = 64584.
The previous prime is 65479. The next prime is 65497. The reversal of 65491 is 19456.
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 65491 - 211 = 63443 is a prime.
It is a Duffinian number.
It is a nialpdrome in base 16.
It is not an unprimeable number, because it can be changed into a prime (65497) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (13) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 336 + ... + 493.
It is an arithmetic number, because the mean of its divisors is an integer number (16600).
65491 is a Friedman number, since it can be written as 16^4-9*5, using all its digits and the basic arithmetic operations.
265491 is an apocalyptic number.
65491 is a deficient number, since it is larger than the sum of its proper divisors (909).
65491 is an equidigital number, since it uses as much as digits as its factorization.
65491 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 908.
The product of its digits is 1080, while the sum is 25.
The square root of 65491 is about 255.9120942824.
The cubic root of 65491 is about 40.3082435463.
The spelling of 65491 in words is "sixty-five thousand, four hundred ninety-one".