3666809 has 2 divisors, whose sum is σ = 3666810. Its totient is φ = 3666808.

The previous prime is 3666797. The next prime is 3666823. The reversal of 3666809 is 9086663.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2805625 + 861184 = 1675^2 + 928^2 .

It is an emirp because it is prime and its reverse (9086663) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3666809 - 2¹² = 3662713 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3666409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1833404 + 1833405.

It is an arithmetic number, because the mean of its divisors is an integer number (1833405).

Almost surely, 2^3666809 is an apocalyptic number.

It is an amenable number.

3666809 is a deficient number, since it is larger than the sum of its proper divisors (1).

3666809 is an equidigital number, since it uses as much as digits as its factorization.

3666809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 38.

The square root of 3666809 is about 1914.8913807316. The cubic root of 3666809 is about 154.2041622295.

The spelling of 3666809 in words is "three million, six hundred sixty-six thousand, eight hundred nine".