1200809 has 2 divisors, whose sum is σ = 1200810. Its totient is φ = 1200808.

The previous prime is 1200799. The next prime is 1200811. The reversal of 1200809 is 9080021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 774400 + 426409 = 880^2 + 653^2 .

It is an emirp because it is prime and its reverse (9080021) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1200809 is a prime.

Together with 1200811, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a plaindrome in base 15.

It is not a weakly prime, because it can be changed into another prime (1200839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600404 + 600405.

It is an arithmetic number, because the mean of its divisors is an integer number (600405).

2^1200809 is an apocalyptic number.

It is an amenable number.

1200809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200809 is an equidigital number, since it uses as much as digits as its factorization.

1200809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 1200809 is about 1095.8143090871. The cubic root of 1200809 is about 106.2897318533.

The spelling of 1200809 in words is "one million, two hundred thousand, eight hundred nine".