79808809 has 2 divisors, whose sum is σ = 79808810. Its totient is φ = 79808808.

The previous prime is 79808789. The next prime is 79808821. The reversal of 79808809 is 90880897.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58905625 + 20903184 = 7675^2 + 4572^2 .

It is an emirp because it is prime and its reverse (90880897) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 79808809 - 2⁷ = 79808681 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (79805809) 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, 39904404 + 39904405.

It is an arithmetic number, because the mean of its divisors is an integer number (39904405).

Almost surely, 2^79808809 is an apocalyptic number.

It is an amenable number.

79808809 is a deficient number, since it is larger than the sum of its proper divisors (1).

79808809 is an equidigital number, since it uses as much as digits as its factorization.

79808809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 290304, while the sum is 49.

The square root of 79808809 is about 8933.5776148193. The cubic root of 79808809 is about 430.5434070918.

The spelling of 79808809 in words is "seventy-nine million, eight hundred eight thousand, eight hundred nine".