6656661 has 40 divisors (see below), whose sum is σ = 11244288. Its totient is φ = 3888000.

The previous prime is 6656659. The next prime is 6656711. The reversal of 6656661 is 1666566.

It is not a de Polignac number, because 6656661 - 2¹ = 6656659 is a prime.

It is a super-2 number, since 2×6656661² = 88622271337842, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6656621) 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 39 ways as a sum of consecutive naturals, for example, 27501 + ... + 27741.

Almost surely, 2^6656661 is an apocalyptic number.

It is an amenable number.

6656661 is a deficient number, since it is larger than the sum of its proper divisors (4587627).

6656661 is a wasteful number, since it uses less digits than its factorization.

6656661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295 (or 286 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 6656661 is about 2580.0505808995. The cubic root of 6656661 is about 188.1130017035.

The spelling of 6656661 in words is "six million, six hundred fifty-six thousand, six hundred sixty-one".