1389809 has 2 divisors, whose sum is σ = 1389810. Its totient is φ = 1389808.

The previous prime is 1389797. The next prime is 1389811. The reversal of 1389809 is 9089831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 717409 + 672400 = 847^2 + 820^2 .

It is an emirp because it is prime and its reverse (9089831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1389809 - 2²⁰ = 341233 is a prime.

Together with 1389811, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1389209) 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, 694904 + 694905.

It is an arithmetic number, because the mean of its divisors is an integer number (694905).

2^1389809 is an apocalyptic number.

It is an amenable number.

1389809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1389809 is an equidigital number, since it uses as much as digits as its factorization.

1389809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 1389809 is about 1178.9016074296. The cubic root of 1389809 is about 111.5967910161.

The spelling of 1389809 in words is "one million, three hundred eighty-nine thousand, eight hundred nine".