6688999 has 2 divisors, whose sum is σ = 6689000. Its totient is φ = 6688998.

The previous prime is 6688967. The next prime is 6689029. The reversal of 6688999 is 9998866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6688999 - 2⁵ = 6688967 is a prime.

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6688909) 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 as a sum of consecutive naturals, namely, 3344499 + 3344500.

It is an arithmetic number, because the mean of its divisors is an integer number (3344500).

Almost surely, 2^6688999 is an apocalyptic number.

6688999 is a deficient number, since it is larger than the sum of its proper divisors (1).

6688999 is an equidigital number, since it uses as much as digits as its factorization.

6688999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1679616, while the sum is 55.

The square root of 6688999 is about 2586.3099195572. The cubic root of 6688999 is about 188.4171268518.

The spelling of 6688999 in words is "six million, six hundred eighty-eight thousand, nine hundred ninety-nine".