3645809 has 2 divisors, whose sum is σ = 3645810. Its totient is φ = 3645808.

The previous prime is 3645791. The next prime is 3645823. The reversal of 3645809 is 9085463.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2334784 + 1311025 = 1528^2 + 1145^2 .

It is a cyclic number.

It is not a de Polignac number, because 3645809 - 2²⁰ = 2597233 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (3645899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1822904 + 1822905.

It is an arithmetic number, because the mean of its divisors is an integer number (1822905).

Almost surely, 2^3645809 is an apocalyptic number.

It is an amenable number.

3645809 is a deficient number, since it is larger than the sum of its proper divisors (1).

3645809 is an equidigital number, since it uses as much as digits as its factorization.

3645809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 3645809 is about 1909.4001675919. The cubic root of 3645809 is about 153.9092201244.

The spelling of 3645809 in words is "three million, six hundred forty-five thousand, eight hundred nine".