6539691 has 4 divisors (see below), whose sum is σ = 8719592. Its totient is φ = 4359792.

The previous prime is 6539681. The next prime is 6539707. The reversal of 6539691 is 1969356.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 6539691 - 2¹⁹ = 6015403 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6539671) 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, 1089946 + ... + 1089951.

It is an arithmetic number, because the mean of its divisors is an integer number (2179898).

Almost surely, 2^6539691 is an apocalyptic number.

6539691 is a deficient number, since it is larger than the sum of its proper divisors (2179901).

6539691 is a wasteful number, since it uses less digits than its factorization.

6539691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2179900.

The product of its digits is 43740, while the sum is 39.

The square root of 6539691 is about 2557.2819555145. The cubic root of 6539691 is about 187.0046516234.

The spelling of 6539691 in words is "six million, five hundred thirty-nine thousand, six hundred ninety-one".