6688663 has 2 divisors, whose sum is σ = 6688664. Its totient is φ = 6688662.

The previous prime is 6688657. The next prime is 6688673. The reversal of 6688663 is 3668866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6688663 - 2⁵ = 6688631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6688603) 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 as a sum of consecutive naturals, namely, 3344331 + 3344332.

It is an arithmetic number, because the mean of its divisors is an integer number (3344332).

Almost surely, 2^6688663 is an apocalyptic number.

6688663 is a deficient number, since it is larger than the sum of its proper divisors (1).

6688663 is an equidigital number, since it uses as much as digits as its factorization.

6688663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 248832, while the sum is 43.

The square root of 6688663 is about 2586.2449613291. The cubic root of 6688663 is about 188.4139719595.

The spelling of 6688663 in words is "six million, six hundred eighty-eight thousand, six hundred sixty-three".