3866809 has 2 divisors, whose sum is σ = 3866810. Its totient is φ = 3866808.

The previous prime is 3866791. The next prime is 3866839. The reversal of 3866809 is 9086683.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2795584 + 1071225 = 1672^2 + 1035^2 .

It is an emirp because it is prime and its reverse (9086683) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3866809 - 2⁵ = 3866777 is a prime.

It is not a weakly prime, because it can be changed into another prime (3866839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1933404 + 1933405.

It is an arithmetic number, because the mean of its divisors is an integer number (1933405).

Almost surely, 2^3866809 is an apocalyptic number.

It is an amenable number.

3866809 is a deficient number, since it is larger than the sum of its proper divisors (1).

3866809 is an equidigital number, since it uses as much as digits as its factorization.

3866809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 3866809 is about 1966.4203518068. The cubic root of 3866809 is about 156.9582833705.

The spelling of 3866809 in words is "three million, eight hundred sixty-six thousand, eight hundred nine".