80809 has 2 divisors, whose sum is σ = 80810. Its totient is φ = 80808.

The previous prime is 80803. The next prime is 80819. The reversal of 80809 is 90808.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75625 + 5184 = 275^2 + 72^2 .

It is a cyclic number.

It is not a de Polignac number, because 80809 - 2⁵ = 80777 is a prime.

It is not a weakly prime, because it can be changed into another prime (80803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40404 + 40405.

It is an arithmetic number, because the mean of its divisors is an integer number (40405).

2⁸⁰⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

80809 is a deficient number, since it is larger than the sum of its proper divisors (1).

80809 is an equidigital number, since it uses as much as digits as its factorization.

80809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 80809 is about 284.2692385750. The cubic root of 80809 is about 43.2334517421.

Subtracting 80809 from its reverse (90808), we obtain a palindrome (9999).

The spelling of 80809 in words is "eighty thousand, eight hundred nine".