180809 has 4 divisors (see below), whose sum is σ = 184704. Its totient is φ = 176916.

The previous prime is 180799. The next prime is 180811. The reversal of 180809 is 908081.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 180809 - 2⁴ = 180793 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a nialpdrome in base 8 and base 12.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 180809.

It is not an unprimeable number, because it can be changed into a prime (183809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1877 + ... + 1970.

It is an arithmetic number, because the mean of its divisors is an integer number (46176).

2¹⁸⁰⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

180809 is a deficient number, since it is larger than the sum of its proper divisors (3895).

180809 is an equidigital number, since it uses as much as digits as its factorization.

180809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3894.

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 180809 is about 425.2164154875. The cubic root of 180809 is about 56.5466240050.

It can be divided in two parts, 180 and 809, that added together give a palindrome (989).

The spelling of 180809 in words is "one hundred eighty thousand, eight hundred nine".