80820809 has 2 divisors, whose sum is σ = 80820810. Its totient is φ = 80820808.

The previous prime is 80820793. The next prime is 80820829. The reversal of 80820809 is 90802808.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72726784 + 8094025 = 8528^2 + 2845^2 .

It is a cyclic number.

It is not a de Polignac number, because 80820809 - 2⁴ = 80820793 is a prime.

It is not a weakly prime, because it can be changed into another prime (80820829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40410404 + 40410405.

It is an arithmetic number, because the mean of its divisors is an integer number (40410405).

Almost surely, 2^80820809 is an apocalyptic number.

It is an amenable number.

80820809 is a deficient number, since it is larger than the sum of its proper divisors (1).

80820809 is an equidigital number, since it uses as much as digits as its factorization.

80820809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 80820809 is about 8990.0394326165. The cubic root of 80820809 is about 432.3555760890.

The spelling of 80820809 in words is "eighty million, eight hundred twenty thousand, eight hundred nine".