6686181 has 6 divisors (see below), whose sum is σ = 9657830. Its totient is φ = 4457448.

The previous prime is 6686177. The next prime is 6686191. The reversal of 6686181 is 1816866.

It can be written as a sum of positive squares in only one way, i.e., 5022081 + 1664100 = 2241^2 + 1290^2 .

It is not a de Polignac number, because 6686181 - 2² = 6686177 is a prime.

It is a super-2 number, since 2×6686181² = 89410032729522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6686191) 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 5 ways as a sum of consecutive naturals, for example, 371446 + ... + 371463.

Almost surely, 2^6686181 is an apocalyptic number.

It is an amenable number.

6686181 is a deficient number, since it is larger than the sum of its proper divisors (2971649).

6686181 is a wasteful number, since it uses less digits than its factorization.

6686181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742915 (or 742912 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 6686181 is about 2585.7650705352. The cubic root of 6686181 is about 188.3906637969.

The spelling of 6686181 in words is "six million, six hundred eighty-six thousand, one hundred eighty-one".