6531681 has 16 divisors (see below), whose sum is σ = 9443840. Its totient is φ = 4015440.

The previous prime is 6531673. The next prime is 6531683. The reversal of 6531681 is 1861356.

It is not a de Polignac number, because 6531681 - 2³ = 6531673 is a prime.

It is a super-2 number, since 2×6531681² = 85325713371522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6531683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6096 + ... + 7086.

It is an arithmetic number, because the mean of its divisors is an integer number (590240).

Almost surely, 2^6531681 is an apocalyptic number.

It is an amenable number.

6531681 is a deficient number, since it is larger than the sum of its proper divisors (2912159).

6531681 is an equidigital number, since it uses as much as digits as its factorization.

6531681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1033 (or 1007 counting only the distinct ones).

The product of its digits is 4320, while the sum is 30.

The square root of 6531681 is about 2555.7153597379. The cubic root of 6531681 is about 186.9282708874.

The spelling of 6531681 in words is "six million, five hundred thirty-one thousand, six hundred eighty-one".