6686857 has 2 divisors, whose sum is σ = 6686858. Its totient is φ = 6686856.

The previous prime is 6686843. The next prime is 6686861. The reversal of 6686857 is 7586866.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6677056 + 9801 = 2584^2 + 99^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6686857 is a prime.

It is not a weakly prime, because it can be changed into another prime (6686357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3343428 + 3343429.

It is an arithmetic number, because the mean of its divisors is an integer number (3343429).

Almost surely, 2^6686857 is an apocalyptic number.

It is an amenable number.

6686857 is a deficient number, since it is larger than the sum of its proper divisors (1).

6686857 is an equidigital number, since it uses as much as digits as its factorization.

6686857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 483840, while the sum is 46.

The square root of 6686857 is about 2585.8957828961. The cubic root of 6686857 is about 188.3970126028.

Subtracting 6686857 from its reverse (7586866), we obtain a palindrome (900009).

The spelling of 6686857 in words is "six million, six hundred eighty-six thousand, eight hundred fifty-seven".