6689659 has 2 divisors, whose sum is σ = 6689660. Its totient is φ = 6689658.

The previous prime is 6689629. The next prime is 6689681. The reversal of 6689659 is 9569866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6689659 - 2⁹ = 6689147 is a prime.

6689659 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (6689629) 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, 3344829 + 3344830.

It is an arithmetic number, because the mean of its divisors is an integer number (3344830).

Almost surely, 2^6689659 is an apocalyptic number.

6689659 is a deficient number, since it is larger than the sum of its proper divisors (1).

6689659 is an equidigital number, since it uses as much as digits as its factorization.

6689659 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 699840, while the sum is 49.

The square root of 6689659 is about 2586.4375113271. The cubic root of 6689659 is about 188.4233236541.

The spelling of 6689659 in words is "six million, six hundred eighty-nine thousand, six hundred fifty-nine".