79716809 has 2 divisors, whose sum is σ = 79716810. Its totient is φ = 79716808.

The previous prime is 79716787. The next prime is 79716829. The reversal of 79716809 is 90861797.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68641225 + 11075584 = 8285^2 + 3328^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79716809 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (79716829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39858404 + 39858405.

It is an arithmetic number, because the mean of its divisors is an integer number (39858405).

Almost surely, 2^79716809 is an apocalyptic number.

It is an amenable number.

79716809 is a deficient number, since it is larger than the sum of its proper divisors (1).

79716809 is an equidigital number, since it uses as much as digits as its factorization.

79716809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 190512, while the sum is 47.

The square root of 79716809 is about 8928.4270171179. The cubic root of 79716809 is about 430.3779064663.

The spelling of 79716809 in words is "seventy-nine million, seven hundred sixteen thousand, eight hundred nine".