6645609 has 6 divisors (see below), whose sum is σ = 9599226. Its totient is φ = 4430400.

The previous prime is 6645601. The next prime is 6645619. The reversal of 6645609 is 9065466.

It is a happy number.

6645609 is a `hidden beast` number, since 6 + 6 + 45 + 609 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5198400 + 1447209 = 2280^2 + 1203^2 .

It is not a de Polignac number, because 6645609 - 2³ = 6645601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6645601) 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 5 ways as a sum of consecutive naturals, for example, 369192 + ... + 369209.

It is an arithmetic number, because the mean of its divisors is an integer number (1599871).

Almost surely, 2^6645609 is an apocalyptic number.

It is an amenable number.

6645609 is a deficient number, since it is larger than the sum of its proper divisors (2953617).

6645609 is a wasteful number, since it uses less digits than its factorization.

6645609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 738407 (or 738404 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 6645609 is about 2577.9078726750. The cubic root of 6645609 is about 188.0088365395.

The spelling of 6645609 in words is "six million, six hundred forty-five thousand, six hundred nine".