8491 has 4 divisors (see below), whose sum is σ = 9712. Its totient is φ = 7272.

The previous prime is 8467. The next prime is 8501. The reversal of 8491 is 1948.

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 8491 - 2⁷ = 8363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8431) 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, 600 + ... + 613.

It is an arithmetic number, because the mean of its divisors is an integer number (2428).

2⁸⁴⁹¹ is an apocalyptic number.

8491 is a deficient number, since it is larger than the sum of its proper divisors (1221).

8491 is a wasteful number, since it uses less digits than its factorization.

8491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1220.

The product of its digits is 288, while the sum is 22.

The square root of 8491 is about 92.1466222930. The cubic root of 8491 is about 20.4010700451.

The spelling of 8491 in words is "eight thousand, four hundred ninety-one".