6686651 has 4 divisors (see below), whose sum is σ = 7038600. Its totient is φ = 6334704.

The previous prime is 6686611. The next prime is 6686653. The reversal of 6686651 is 1566866.

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 6686651 - 2¹⁴ = 6670267 is a prime.

It is a super-2 number, since 2×6686651² = 89422603191602, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6686653) 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, 175946 + ... + 175983.

It is an arithmetic number, because the mean of its divisors is an integer number (1759650).

Almost surely, 2^6686651 is an apocalyptic number.

6686651 is a deficient number, since it is larger than the sum of its proper divisors (351949).

6686651 is a wasteful number, since it uses less digits than its factorization.

6686651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351948.

The product of its digits is 51840, while the sum is 38.

The square root of 6686651 is about 2585.8559511311. The cubic root of 6686651 is about 188.3950779529.

It can be divided in two parts, 6686 and 651, that added together give a palindrome (7337).

The spelling of 6686651 in words is "six million, six hundred eighty-six thousand, six hundred fifty-one".