79666309 has 2 divisors, whose sum is σ = 79666310. Its totient is φ = 79666308.

The previous prime is 79666253. The next prime is 79666313. The reversal of 79666309 is 90366697.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77176225 + 2490084 = 8785^2 + 1578^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79666309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79666339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39833154 + 39833155.

It is an arithmetic number, because the mean of its divisors is an integer number (39833155).

Almost surely, 2^79666309 is an apocalyptic number.

It is an amenable number.

79666309 is a deficient number, since it is larger than the sum of its proper divisors (1).

79666309 is an equidigital number, since it uses as much as digits as its factorization.

79666309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 367416, while the sum is 46.

The square root of 79666309 is about 8925.5985233484. The cubic root of 79666309 is about 430.2870068781.

The spelling of 79666309 in words is "seventy-nine million, six hundred sixty-six thousand, three hundred nine".