5645809 has 4 divisors (see below), whose sum is σ = 6080116. Its totient is φ = 5211504.

The previous prime is 5645779. The next prime is 5645851. The reversal of 5645809 is 9085465.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9085465 = 5 ⋅1817093.

It can be written as a sum of positive squares in 2 ways, for example, as 717409 + 4928400 = 847^2 + 2220^2 .

It is a cyclic number.

It is not a de Polignac number, because 5645809 - 2⁷ = 5645681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5645609) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 217134 + ... + 217159.

It is an arithmetic number, because the mean of its divisors is an integer number (1520029).

Almost surely, 2^5645809 is an apocalyptic number.

It is an amenable number.

5645809 is a deficient number, since it is larger than the sum of its proper divisors (434307).

5645809 is a wasteful number, since it uses less digits than its factorization.

5645809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434306.

The product of its (nonzero) digits is 43200, while the sum is 37.

The square root of 5645809 is about 2376.0911177815. The cubic root of 5645809 is about 178.0637002159.

The spelling of 5645809 in words is "five million, six hundred forty-five thousand, eight hundred nine".