6689509 has 4 divisors (see below), whose sum is σ = 6700320. Its totient is φ = 6678700.

The previous prime is 6689503. The next prime is 6689537. The reversal of 6689509 is 9059866.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6689509 - 2¹⁹ = 6165221 is a prime.

It is a super-2 number, since 2×6689509² = 89499061322162, which contains 22 as substring.

It is a Duffinian number.

6689509 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6689503) 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 3 ways as a sum of consecutive naturals, for example, 4417 + ... + 5734.

It is an arithmetic number, because the mean of its divisors is an integer number (1675080).

Almost surely, 2^6689509 is an apocalyptic number.

It is an amenable number.

6689509 is a deficient number, since it is larger than the sum of its proper divisors (10811).

6689509 is a wasteful number, since it uses less digits than its factorization.

6689509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10810.

The product of its (nonzero) digits is 116640, while the sum is 43.

The square root of 6689509 is about 2586.4085137503. The cubic root of 6689509 is about 188.4219153258.

The spelling of 6689509 in words is "six million, six hundred eighty-nine thousand, five hundred nine".