6645309 has 16 divisors (see below), whose sum is σ = 9710400. Its totient is φ = 4008960.

The previous prime is 6645293. The next prime is 6645313. The reversal of 6645309 is 9035466.

It is a happy number.

It is not a de Polignac number, because 6645309 - 2⁴ = 6645293 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a self number, because there is not a number n which added to its sum of digits gives 6645309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6645319) 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 in 15 ways as a sum of consecutive naturals, for example, 11229 + ... + 11805.

It is an arithmetic number, because the mean of its divisors is an integer number (606900).

Almost surely, 2^6645309 is an apocalyptic number.

It is an amenable number.

6645309 is a deficient number, since it is larger than the sum of its proper divisors (3065091).

6645309 is a wasteful number, since it uses less digits than its factorization.

6645309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 940.

The product of its (nonzero) digits is 19440, while the sum is 33.

The square root of 6645309 is about 2577.8496852997. The cubic root of 6645309 is about 188.0060074284.

The spelling of 6645309 in words is "six million, six hundred forty-five thousand, three hundred nine".