79816420309 has 2 divisors, whose sum is σ = 79816420310. Its totient is φ = 79816420308.

The previous prime is 79816420253. The next prime is 79816420331. The reversal of 79816420309 is 90302461897.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78020779684 + 1795640625 = 279322^2 + 42375^2 .

It is a cyclic number.

It is not a de Polignac number, because 79816420309 - 2²¹ = 79814323157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79816421309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39908210154 + 39908210155.

It is an arithmetic number, because the mean of its divisors is an integer number (39908210155).

Almost surely, 2^79816420309 is an apocalyptic number.

It is an amenable number.

79816420309 is a deficient number, since it is larger than the sum of its proper divisors (1).

79816420309 is an equidigital number, since it uses as much as digits as its factorization.

79816420309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184, while the sum is 49.

The spelling of 79816420309 in words is "seventy-nine billion, eight hundred sixteen million, four hundred twenty thousand, three hundred nine".