3821809 has 2 divisors, whose sum is σ = 3821810. Its totient is φ = 3821808.

The previous prime is 3821803. The next prime is 3821813. The reversal of 3821809 is 9081283.

3821809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2900209 + 921600 = 1703^2 + 960^2 .

It is a cyclic number.

It is not a de Polignac number, because 3821809 - 2³ = 3821801 is a prime.

It is not a weakly prime, because it can be changed into another prime (3821801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1910904 + 1910905.

It is an arithmetic number, because the mean of its divisors is an integer number (1910905).

Almost surely, 2^3821809 is an apocalyptic number.

It is an amenable number.

3821809 is a deficient number, since it is larger than the sum of its proper divisors (1).

3821809 is an equidigital number, since it uses as much as digits as its factorization.

3821809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 3821809 is about 1954.9447562527. The cubic root of 3821809 is about 156.3470386020.

The spelling of 3821809 in words is "three million, eight hundred twenty-one thousand, eight hundred nine".