6440609 has 6 divisors (see below), whose sum is σ = 7492194. Its totient is φ = 5520480.

The previous prime is 6440587. The next prime is 6440641. The reversal of 6440609 is 9060446.

It can be written as a sum of positive squares in only one way, i.e., 4558225 + 1882384 = 2135^2 + 1372^2 .

It is not a de Polignac number, because 6440609 - 2¹² = 6436513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6440699) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 65672 + ... + 65769.

It is an arithmetic number, because the mean of its divisors is an integer number (1248699).

Almost surely, 2^6440609 is an apocalyptic number.

It is an amenable number.

6440609 is a deficient number, since it is larger than the sum of its proper divisors (1051585).

6440609 is a wasteful number, since it uses less digits than its factorization.

6440609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131455 (or 131448 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 6440609 is about 2537.8354950627. The cubic root of 6440609 is about 186.0554137895.

The spelling of 6440609 in words is "six million, four hundred forty thousand, six hundred nine".