6491 has 2 divisors, whose sum is σ = 6492.
Its totient is φ = 6490.
The previous prime is 6481. The next prime is 6521. The reversal of 6491 is 1946.
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 6491 - 26 = 6427 is a prime.
It is a Sophie Germain prime.
It is a Chen prime.
It is not a weakly prime, because it can be changed into another prime (6421) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3245 + 3246.
It is an arithmetic number, because the mean of its divisors is an integer number (3246).
26491 is an apocalyptic number.
6491 is a deficient number, since it is larger than the sum of its proper divisors (1).
6491 is an equidigital number, since it uses as much as digits as its factorization.
6491 is an evil number, because the sum of its binary digits is even.
The product of its digits is 216, while the sum is 20.
The square root of 6491 is about 80.5667425182.
The cubic root of 6491 is about 18.6539383183.
The spelling of 6491 in words is "six thousand, four hundred ninety-one".